FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

ELECTRONIC FRONTIER FOUNDATION,          
                 Plaintiff-Appellee,             No. 09-17235
                v.                                 D.C. Nos.
OFFICE OF THE DIRECTOR OF                    3:08-cv-01023-JSW
                                              3:08-cv-02997-JSW
NATIONAL INTELLIGENCE;
DEPARTMENT OF JUSTICE,                             OPINION
            Defendants-Appellants.
                                         
        Appeal from the United States District Court
           for the Northern District of California
         Jeffrey S. White, District Judge, Presiding

                    Argued and Submitted
         January 12, 2010—San Francisco, California

                     Filed February 9, 2010

   Before: Myron H. Bright,* Michael Daly Hawkins, and
            Milan D. Smith, Jr., Circuit Judges.

                   Opinion by Judge Hawkins




   *The Honorable Myron H. Bright, Senior United States Circuit Judge
for the Eighth Circuit, sitting by designation.

                               2313
2318                    EFF v. ODNI


                         COUNSEL

Douglas N. Letter and Scott McIntosh, United States Depart-
ment of Justice, Civil Division, Washington, D.C., for the
defendants-appellants.

Marcia Hofmann, San Francisco, California, for the plaintiff-
appellee.


                         OPINION

HAWKINS, Circuit Judge:

   In the wake of the September 11, 2001 terrorist attacks, the
President authorized the National Security Agency (“NSA”)
to conduct a warrantless, electronic surveillance program on
millions of American telephones. Numerous lawsuits have
claimed the program was illegal and unconstitutional, e.g., Al-
Haramain Islamic Foundation, Inc. v. Bush, 

,
1192-93 (9th Cir. 2007), including a consolidated action for
damages against allegedly cooperating telecommunications
providers, see In re NSA Telecomms. Records Litig., 633 F.
Supp. 2d 949, 959 (N.D. Cal. 2009); see also U.S. Dep’t of
Justice, Office of Inspector Gen., A Review of the Federal
Bureau of Investigation’s Use of Exigent Letters and Other
Informal Requests for Telephone Records 20-25 (Jan. 2010)
(describing three unnamed telecommunications carriers’
                             EFF v. ODNI                           2319
cooperation with the FBI). The merits of those claims, how-
ever, are not at issue here.

   This case concerns the discussions between telecommuni-
cations carriers (including their lobbyists and attorneys) and
the government, as the carriers sought retroactive liability
protection for any participation in the program. This appeal
concerns the extent to which the public has the right to infor-
mation about those discussions and related lobbying efforts
under the Freedom of Information Act (“FOIA”).

                        I.   BACKGROUND

A.     Enactment of the Foreign Intelligence Surveillance
       Act Amendments

  Efforts to provide liability protection for the providers
began in 2007. In April of that year, as part of a broader dis-
cussion of reforming electronic surveillance laws, the Depart-
ment of Justice (“DOJ”) sent a legislative proposal to
Congress, which included a provision creating retroactive
immunity for telecommunications providers alleged to have
participated in the surveillance activities. In August 2007,
Congress enacted the Protect America Act of 2007 (“PAA”),
Pub. L. No. 110-55, 121 Stat. 552, a temporary measure,
which did not include a liability shield.

   Contemporaneously with the PAA debate, news organiza-
tions such as The New York Times and Newsweek reported on
a “campaign” involving “some of Washington’s most promi-
nent lobbying and law firms”1 to pressure the Bush adminis-
  1
     The Newsweek article included the following:
        Among those coordinating the industry’s effort are two well-
      connected capital players who both worked for President George
      H.W. Bush: Verizon general counsel William Barr, who served
      as attorney general under 41, and AT&T senior executive vice
      president James Cicconi, who was the elder Bush’s deputy chief
      of staff.
2320                       EFF v. ODNI
tration to “quickly approve a measure wiping out all private
lawsuits against them for assisting” with the warrantless sur-
veillance program. The news accounts highlighted the provid-
ers’ “hidden role in the political battle,” and Newsweek
claimed Director of National Intelligence Mike McConnell
(“McConnell”) had “raise[d] the stakes,” stating in a recent
interview that the lawsuits could “bankrupt these companies.”

   Congress designed the PAA as a stopgap, and allowed it to
expire on February 16, 2008. One day before the PAA’s expi-
ration, McConnell discussed the need for statutory protection
for the carriers, stating in a TV interview, “The companies are
telling us if you can’t protect us, the cooperation you need is
not going to be there.” On February 23, DOJ and the Office
of the Director of National Intelligence (“ODNI”) issued a
joint press release noting the “private partners are cooperating
for the time being,” but the government also expressed con-
cern because the carriers “have indicated that they may well
discontinue cooperation if the uncertainty [over their liability
exposure] persists.” News reports claimed AT&T in fact
stopped cooperating with the government for six days after
the expiration of the PAA. Similar reports indicated Verizon
expressed its concerns to the government but did not cease its
assistance.

      Working with them are a battery of major D.C. lobbyists and
   lawyers who are providing “strategic advice” to the companies on
   the issue, according to sources familiar with the campaign who
   asked not to be identified talking about it. Among the players,
   these sources said: powerhouse Republican lobbyists Charlie
   Black and Wayne Berman (who represent AT&T and Verizon,
   respectively), former GOP senator and U.S. ambassador to Ger-
   many Dan Coats (a lawyer at King & Spaulding who is represent-
   ing Sprint), former Democratic Party strategist and one-time
   assistant secretary of State Tom Donilon (who represents Veri-
   zon), former deputy attorney general Jamie Gorelick (whose law
   firm also represents Verizon) and Brad Berenson, a former assis-
   tant White House counsel under President George W. Bush who
   now represents AT&T.
                            EFF v. ODNI                          2321
   In July 2008, Congress passed, and the President signed,
the Foreign Intelligence Surveillance Act of 1978 Amend-
ments Act of 2008 (“FISA Amendments Act”), Pub. L. No.
110-261, 122 Stat. 2436, updating FISA on a more permanent
basis than did the PAA. As their lobbyists had sought, the leg-
islation included a liability shield for the carriers. Under Title
VIII of the Act, section 802, “Procedures for Implementing
Statutory Defenses,” established the immunity procedure.

  Specifically, section 802 provided that “a civil action may
not lie or be maintained in a Federal or State court against any
person for providing assistance to an element of the intelli-
gence community, and shall be promptly dismissed,” so long
as the Attorney General certified either that a defendant pro-
vided assistance pursuant to a number of reasons, such as
court order or presidential authorization, see § 802(a)(1)-(4),
122 Stat. at 2468-69, or certified that “the person did not pro-
vide the alleged assistance,” 

(emphasis added).

B.    EFF’s FOIA Requests

   After passage of the PAA but before enactment of the FISA
Amendments Act, the Electronic Frontier Foundation (“EFF”)
made a FOIA request to ODNI and five DOJ components
(together “Defendants” or “the government”),2 seeking all
records from September 1, 2007, through December 21, 2007,
concerning “briefing, discussions, or other exchanges” agency
officials had with 1) members of Congress, and “2) represen-
tatives or agents of telecommunications companies concern-
ing amendments to FISA, including any discussion of
immunizing telecommunications companies or holding them
otherwise unaccountable for their role in government surveil-
lance activities.” Elec. Frontier Found. v. Office of the Dir. of
  2
   The five DOJ components were the Office of the Attorney General
(“OAG”), the Office of Legislative Affairs (“OLA”), the Office of Legal
Policy (“OLP”), the Office of Legal Counsel (“OLC”), and DOJ’s
National Security Division (“NSD”).
2322                          EFF v. ODNI
Nat’l Intelligence, 

, 1184 (N.D. Cal.
2008) (“EFF”).

   Some four months later, EFF submitted a second round of
FOIA requests to the same agencies seeking “all agency
records” concerning briefings, discussions, or other exchanges
between the agencies and “representatives or agents of tele-
communications companies concerning amendments to
FISA,” or shielding the companies from liability as a result of
their cooperation with government surveillance activities.
This round of FOIA requests also sought information regard-
ing communications from the agencies to members of Con-
gress or their staffs, as well as agency communications,
regardless of subject matter, with a number of named, high-
profile telecommunications industry employees and lobbyists.3

   In both FOIA letters, EFF sought expedited processing of
their requests. See 5 U.S.C. § 552(a)(6)(E)(v)(II) (2000), 32
  3
   EFF’s specific FOIA request sought all records:
      A.   from December 21, 2007 to the present concerning briefs,
           discussions, or other exchanges, any [agency] official has
           had with representatives or agents of telecommunications
           companies concerning amendments to FISA, including any
           discussion of immunizing telecommunications companies or
           holding them otherwise unaccountable for their role in gov-
           ernment surveillance activities;
      B.   from December 21, 2007 to the present concerning briefings,
           discussions, or other communications from any OAG offi-
           cial to any member of the Senate or House of Representa-
           tives or their staffs;
      C.   from December 21, 2007 to the present concerning any com-
           munications, discussions, or other exchanges regardless of
           subject that any [agency] official has had with Charlie
           Black, Wayne Berman, Dan Coats, Tom Donilon, Jamie
           Gorelick or Brad Berenson; and
      D.   from January 1, 2007 to the present that are responsive to
           the categories above, and have not yet been produced in
           response to previous EFF FOIA requests.
                        EFF v. ODNI                       2323
C.F.R. § 1700.12(c)(2) (2007), and 28 C.F.R. § 16.5(d)(1)(ii).
When the agencies failed to timely respond, EFF filed two
separate actions, which were later consolidated by the district
court.

C.   Procedural History

   On April 4, 2008, the district court granted a preliminary
injunction requiring ODNI and DOJ to expedite processing of
EFF’s December 2007 FOIA requests. 

. The parties negotiated a schedule for processing the
June 2008 requests.

   In response to the preliminary injunction, ODNI and DOJ
released many documents, but withheld others pursuant to a
number of FOIA exemptions and privileges. Under Exemp-
tion 5 (protecting “inter-agency or intra-agency” documents
privileged in civil litigation, 5 U.S.C. § 552(b)(5) (2006)),
Defendants withheld email messages and other information
exchanged between the agencies and Congress, the agencies
and the telecommunications carriers, and the agencies and
other parts of the Executive Branch, including the White
House.

   Defendants also withheld the identities of telecommunica-
tions company representatives under Exemption 3 (permitting
the withholding of information “specifically exempted from
disclosure by statute,” 5 U.S.C. § 552(b)(3)), and Exemption
6 (permitting withholding of certain personnel, medical, and
similar files for which disclosure “would constitute a clearly
unwarranted invasion of personal privacy.” 5 U.S.C.
§ 552(b)(6)).

  EFF challenged withholdings related to unclassified com-
munications between and among Executive agencies, Con-
gress, the White House, and telecommunications carriers,
concerning amendments to FISA. It also challenged Defen-
dants’ withholding of the identities of individual agents or
2324                       EFF v. ODNI
representatives of the carriers within both the released and
withheld communications. The parties each moved for sum-
mary judgment, which they agreed to consolidate, and the dis-
trict court denied the government’s motion, granted EFF’s
cross-motion, and ordered the government to disclose the con-
tested documents.

   After the district court rejected Defendants’ motions for
reconsideration and refused a temporary stay pending the
Solicitor General’s determination regarding appeal of the dis-
closure order, Defendants sought the stay in this court. We
granted a stay pending appeal to allow the Solicitor General
the opportunity to decide which part(s) of the summary judg-
ment order to appeal.

   Defendants decided not to appeal the district court order as
it pertained to information Defendants exchanged with Con-
gress and with the telecommunications firms, and the govern-
ment then disclosed the content of all communications
between the agencies and Congress and the agencies and tele-
communications carriers, though redacted the identities of
telecommunications firms and their agents or representatives.
This substantial disclosure left only two types of information
Defendants continue to withhold.

   Under Exemption 5, Defendants are withholding materials
claimed to have been circulated solely within the Executive
Branch. Defendants also continue to withhold the previously
redacted identities of telecommunications firms and their
agents or representatives involved in the FISA Amendments
Act communications under Exemption 3 and Exemption 6.

                     II.    DISCUSSION

A.     Standard of Review under FOIA

  [1] FOIA was enacted to create a “judicially enforceable
public right to secure” government documents. EPA v. Mink,
                          EFF v. ODNI                         2325

, 80 (1973); see also U.S. Dep’t of State v. Ray,

, 173 (1991) (FOIA “was enacted to facilitate
public access to Government documents.”). The statutory
scheme provides public access to government information
“shielded unnecessarily” from the public and establishes a
“judicially enforceable public right to secure such information
from possibly unwilling official hands.” Dep’t of Air Force v.
Rose, 

, 361 (1976) (internal quotation marks
omitted). FOIA’s purpose was thus to “ensure an informed
citizenry, vital to the functioning of a democratic society,
needed to check against corruption and to hold the governors
accountable to the governed.” John Doe Agency v. John Doe
Corp., 

, 152 (1989) (internal quotation marks
omitted).

   [2] “At the same time, FOIA contemplates that some infor-
mation may legitimately be kept from the public.” Lahr v.
NTSB, 

, 973 (9th Cir. 2009). The statute contains
nine exemptions, pursuant to which the government can with-
hold information otherwise available for disclosure. See 5
U.S.C. § 552(b)(1)-(9) (2006). “FOIA’s ‘strong presumption
in favor of disclosure’ means that an agency that invokes one
of the statutory exemptions to justify the withholding of any
requested documents or portions of documents bears the bur-
den of demonstrating that the exemption properly applies to
the documents.” 

(quoting 

). Because of its overarching goal of public disclosure,
FOIA “exemptions are to be interpreted narrowly.” 

judgment, we employ a two-step standard of
review in FOIA cases. Lion Raisins Inc. v. U.S. Dep’t of
Agric., 

, 1078 (9th Cir. 2004). First, whether,
de novo, “an adequate factual basis exists to support the dis-
trict court’s decisions.” Milner v. U.S. Dep’t of the Navy, 

, 963 (9th Cir. 2009). If so, “ ‘then we review the dis-
trict court’s conclusions of fact for clear error, while legal rul-
ings, including its decision that a particular exemption
applies, are reviewed de novo.’ ” 

v. Dep’t
2326                      EFF v. ODNI
of Interior, 

, 1135 (9th Cir. 2008)). The burden
rests on the government to justify its decision to exclude dis-
closures under FOIA. U.S. Dep’t of Justice v. Reporters
Comm. for Freedom of the Press, 

, 755 (1989)
(“Reporters Comm.”).

B.     Information on Carriers’ and their Agents’ Lobbying
       Communications

     1.   FOIA Exemption 3

   The government argues it is entitled to withhold the names
of the participating carriers and their agents pursuant to FOIA
Exemption 3. Due to confusion evident in the parties’ cross-
motions for summary judgment, the district court did not
squarely address the factual or legal basis of the government’s
Exemption 3 argument.

   [3] FOIA Exemption 3 allows a responding agency to
withhold information “specifically exempted from disclosure
by statute.” 5 U.S.C. § 552(b)(3). The government argues two
statutes justify its withholdings: First, Section 103(c)(7) of the
National Security Act of 1947, obligating the Director of
National Intelligence to “protect intelligence sources and
methods from unauthorized disclosure,” 50 U.S.C. § 403-
1(i)(1) (2006); see also CIA v. Sims, 

, 178-79
(1985); and second, Section 6 of the National Security
Agency Act of 1959, which prevents “disclosure of the orga-
nization or any function of the National Security Agency, or
any information with respect to the activities thereof, or of the
names, titles, salaries, or number of persons employed by
such agency,” Pub. L. No. 86-36, 73 Stat. 63, codified at 50
U.S.C. § 402 note.

   Under these statutes and Exemption 3, the government’s
summary judgment brief argued, “ODNI and DOJ withheld
information that could reveal whether any particular telecom-
munications carrier has assisted, or may in the future assist,
                        EFF v. ODNI                       2327
the government with intelligence activities.” The government
claimed disclosure “could deter telecommunications compa-
nies from assisting the government in the future,” and disclo-
sure “provides our adversaries with valuable information
about our intelligence sources, methods, and capabilities.”

   [4] The government’s argument was predicated on the fol-
lowing inference: Revealing the identity of carriers and their
agents working for a carrier liability shield would allow for-
eign intelligence agents to determine contours of NSA intelli-
gence operations, sources, and methods. In other words,
knowledge of which firms were and were not lobbying for lia-
bility protection could lead to inferences regarding the firms
that participate in the surveillance program. EFF disputes the
propriety of this inference. However, because the district
court did not address Exemption 3 due to confusion in the
parties’ summary judgment briefing, we remand for the dis-
trict court to address these claims in the first instance. See
Pac. Fisheries, Inc. v. United States, 

, 1147
(9th Cir. 2008).

   EFF’s motion opposing the government’s summary judg-
ment motion is likely the source of the district court’s confu-
sion. The government relied on the following statement from
EFF’s motion in claiming EFF abandoned its objection to the
government’s withholding the names of telecommunications
firms and agents under Exemption 3: “EFF has decided not to
challenge . . . the withholding of any material under Exemp-
tions 1, 2, 3, or 7(E).” The district court, in passing, men-
tioned this same statement from EFF’s motion in failing to
discuss Exemption 3 in its summary judgment ruling.

   Although EFF’s statement seems to abandon its Exemption
3 challenge, other language contradicts such a conclusion. For
example, the sentence quoted above ended in a footnote,
which included the following: “In some cases, the govern-
ment claims Exemptions 1 and/or 3 in conjunction with
Exemptions 5 and/or 6. EFF continues to challenge the
2328                     EFF v. ODNI
Exemption 5 and 6 withholdings to the extent the records can
be disclosed without revealing classified information or the
government’s intelligence sources and methods.” In the same
paragraph with the confusing sentence, EFF went on to claim,
“as a result of EFF’s efforts to narrow the scope of the litiga-
tion, the only material still at issue relates to unclassified
communications between and among executive agencies,
Congress, the White House, and telecommunications compa-
nies concerning amendments to FISA, and the identities of
individual agents or representatives of the carriers within
those communications.”

   The government’s reply to EFF claimed EFF had “clearly
abandoned its challenge of Exemption 3 withholdings,” and
the government did not discuss the merits of whether releas-
ing names of telecommunications firms and their agents was
adequately withheld under Exemption 3.

   EFF countered, claiming the government’s arguments
under Exemption 3 were “coextensive” with the Exemption 6
arguments. EFF explained, “[a]s noted in EFF’s opening
brief, despite not challenging Exemption 3 directly, ‘EFF con-
tinues to challenge the Exemption 5 and 6 withholdings to the
extent that records can be disclosed without revealing classi-
fied information or the government’s intelligence sources and
methods.’ ” It continued, “[t]he identities of the individuals
contacting the government would reveal neither classified
information nor the government’s intelligence sources and
methods.” The parties thus placed the district court in the dif-
ficult position of determining, over disputed claims, whether
Exemption 3 claims were actually at issue.

   The district court seemed to accept the government’s asser-
tion that EFF abandoned its Exemption 3 challenge, but, then,
when it found the government could not withhold the same
documents under Exemption 6, it ordered them released with-
out considering the documents for which the government also
claimed Exemption 3. Assuming the district court found EFF
                        EFF v. ODNI                      2329
abandoned its Exemption 3 arguments, these would appear to
be validly withheld documents under the government’s sup-
posedly unchallenged Exemption 3 claim.

   A single valid exemption is sufficient to support withhold-
ing. See 

n.8; Painting Indus. of Haw.
Mkt. Recovery Fund v. U.S. Dep’t of Air Force, 

,
1486 (9th Cir. 1994). Therefore, if the district court found
EFF had abandoned its argument against Exemption 3 with-
holding, the documents the government withheld pursuant to
Exemption 3 should not have been ordered released. If the
district court found EFF was actually challenging whether
releasing the names of telecommunications firms and their
agents constituted an unauthorized disclosure of intelligence
sources and methods, it should have undertaken that analysis.

   [5] Based on the nature of EFF’s challenge, we take the
latter position. Because the district court did not review the
governments’ arguments pursuant to Exemption 3, we remand
for it to conduct the Exemption 3 review. See Pac. Fisheries,

. A remand is particularly appropriate
because our two-step review of FOIA determinations presup-
poses the district court has determined a contested issue. See

; Berman v. CIA, 

,
1139-40 (9th Cir. 2007).

   The record indicates EFF never conceded its challenge to
withholding the names of the carriers and their agents despite
its statement it was abandoning its Exemption 3 challenge.
Thus, finding EFF did relinquish this challenge, and deciding
the issue solely under Exemption 6, would not be an accurate
reading of EFF’s arguments as a whole, nor is it reason to
reject out-of-hand all challenges to the government’s with-
holding of the carriers’ and agents’ identities.

   The government claims that releasing identities of firms
and individuals working for a carrier liability shield will
create an inference of the government’s sources of intelli-
2330                     EFF v. ODNI
gence. Determining whether this claim is meritorious may
require factual determinations, and it also may require—
though it may not—the reviewing court to view the disputed
documents in camera as opposed to simply relying on the
Vaughn indices currently in the record. Further, our well-
established procedure for reviewing FOIA exemption deter-
minations is not perfectly applicable where, as here, the dis-
trict court did not make an actual determination. See 

; 

.

   [6] For the foregoing reasons, we vacate and remand the
district court’s Exemption 3 analysis, to the extent one exists,
for the district court to address whether the government prop-
erly withheld telecommunications firms’ and their agents’
identities pursuant to FOIA Exemption 3.

    2.   FOIA Exemption 6

   Defendants also claim they are entitled to withhold the
names of the telecommunications carriers and their agents
pursuant to Exemption 6 to protect the agents’ personal pri-
vacy. Because satisfying a single FOIA exemption is all the
government must show to withhold a given piece of informa-
tion, see 

n.2, we must also reach
the Exemption 6 issue.

   The district court found the “public interest in an informed
citizenry” outweighed the carriers’ agents’ “not substantial”
privacy interests. For the reasons explained below, we affirm
the district court on the Exemption 6 summary judgment grant
for EFF.

   [7] Exemption 6 removes “personnel and medical files and
similar files the disclosure of which would constitute a clearly
unwarranted invasion of personal privacy” from FOIA’s dis-
closure requirements. 5 U.S.C. § 552(b)(6). In considering
whether Exemption 6 applies to a particular request for infor-
mation, we must consider, first, whether the information is
                         EFF v. ODNI                        2331
contained in a personnel, medical, or “similar” file, and, sec-
ond, “whether release of the information would constitute a
clearly unwarranted invasion of the person’s privacy.” U.S.
Dep’t of State v. Wash. Post Co., 

, 602 (1982)
(finding citizenship status properly withheld under Exemption
6). In conducting this second inquiry, we balance the individ-
ual’s privacy interest against “the extent to which FOIA’s
central purpose of opening agency action to public scrutiny
would be served by disclosure.” U.S. Dep’t of Def. v. Fed.
Labor Relations Auth., 

, 491 (1994); see 

(A court “must balance the privacy interest
protected by the exemptions against the public interest in gov-
ernment openness that would be served by disclosure.”).

   The first question is thus whether communications docu-
mented in the records in question constitute “similar” infor-
mation as that contained in personnel and medical files under
Exemption 6. As the government points out, EFF does not
contest whether the emails are “similar files.” Though this
may be a closer question than the government describes, we
assume without deciding that the documents at issue here
qualify as “similar files.” See Nat’l Ass’n of Home Builders
v. Norton, 

, 33 (D.C. Cir. 2002) (assuming with-
out deciding that the documents in question were similar files
because invasion of privacy question was dispositive and
more straightforward).

   [8] We next consider “whether release of the information
would constitute a clearly unwarranted invasion of that per-
son’s privacy.” Wash. Post 

. “[T]o deter-
mine whether a record is properly withheld, we must balance
the privacy interest protected by the exemptions against the
public interest in government openness that would be served
by disclosure.” 

.

  The district court concluded “that there is some, although
not a substantial, privacy interest in the withheld documents
indicating the identities of the private individuals and entities
2332                     EFF v. ODNI
who communicated with the ODNI and DOJ in connection
with the FISA amendments.” It found, however, “that the
public interest in an informed citizenry weighs in favor of dis-
closure” because “there is a strong public interest in disclo-
sure of the identity of the individuals who contacted the
government . . . to protect telecommunications companies
from legal liability for their role in government surveillance
activities.” We agree.

   [9] Because Exemption 6 cases often involve a dispute
over whether to redact a government employee’s name, or a
record of an individual in a large government database, there
is little authority on the privacy interest under Exemption 6
when a private individual voluntarily seeks to engage with
and persuade the government on a policy position. However,
as described below, the few cases considering a private party
attempting to influence government policy typically find in
favor of disclosure, lacking countervailing concerns not pres-
ent in this case. See, e.g., Alliance for the Wild Rockies v.
Dep’t of the Interior, 

, 36-37 (D.D.C. 1999).

    Perhaps the most factually analogous case is People for the
American Way Foundation v. National Park Service, in which
a district court rejected Exemption 6 withholding of the iden-
tities of a group urging the National Park Service to alter the
video shown at the Lincoln Memorial to remove “photographs
and video coverage of demonstrations that occurred at the
Lincoln Memorial, including gay rights, pro-choice and anti-
Vietnam War footage.” 

, 288-89 (D.D.C.
2007). Discussing Exemption 6, the court stated, “[w]hen a
citizen petitions his government to take some action, courts
have generally declined to find the identity of the citizen to
be information that raises privacy concerns under exemption
6.” 

(internal quotation marks omitted).

   The cases considering this issue largely reason along the
same lines. Although some cases have found little public
interest in disclosing the name of a constituent writing to a
                        EFF v. ODNI                       2333
member of Congress, they recognize the obvious distinction
between that and the public’s interest in knowing which polit-
ically active groups affect government decision making. See

letters from more involved
forms of policy influence). Compare Strout v. U.S. Parole
Comm’n, 

, 139 (6th Cir. 1994) (finding consider-
able privacy interest in individuals writing to oppose parole
request), and Kidd v. Dep’t of Justice, 

,
297 (D.D.C. 2005) (“Providing personal identifying informa-
tion commonly found in constituent letters [to members of
Congress] does not advance the purposes of FOIA and, as
such, may be withheld from FOIA requests.”), and Voinche
v. FBI, 

, 330 (D.D.C. 1996) (“There is no
reason to believe that the public will obtain a better under-
standing of the workings of various agencies by learning the
identities of . . . private citizens who wrote to government
officials . . . .”), with Kurzon v. Dep’t of Health & Human
Servs., 

, 69-70 (1st Cir.1981) (rejecting govern-
ment’s Exemption 6 argument to withhold names of scientists
turned down for research funding, holding that although the
“protection of professional reputation, even in this strict
sense, is not beyond the purview of exemption 6, it is not at
its core”), and Lardner v. U.S. Dep’t of Justice, No. Civ.A.03-
0180(JDB), 

, at *18 (D.D.C. Mar. 31, 2005)
(holding public interest in identifying persons influencing
presidential pardon power outweighed modest privacy inter-
est), and Judicial Watch of Florida, Inc. v. U.S. Dep’t of Jus-
tice, 

, 18 (D.D.C. 2000) (“Depriving the
public of knowledge of the writer’s identity would deprive the
public of a fact which could suggest that their Justice Depart-
ment had been steered by political pressure rather than by the
relevant facts and law.”), and Alliance for the Wild 

(names and addresses of individuals
who submitted comments on proposed rulemaking could not
be withheld under Exemption 6 because of public interest in
disclosure).

   Here, we balance the public interest in obtaining informa-
tion about the effects of lobbying on government decision
2334                     EFF v. ODNI
making against the privacy concerns of telecommunications
industry lobbyists in keeping their names and the nature of
their employment activities private. Under Exemption 6, our
inquiry is primarily concerned with privacy, here that of the
carriers’ agents and lobbyists.

   [10] There is a clear public interest in public knowledge of
the methods through which well-connected corporate lobby-
ists wield their influence. As the Supreme Court has
explained, “[o]fficial information that sheds light on an agen-
cy’s performance of its statutory duties” merits disclosure.
Reporters 

.

   [11] With knowledge of the lobbyists’ identities, the public
will be able to determine how the Executive Branch used
advice from particular individuals and corporations in reach-
ing its own policy decisions. Such information will allow the
public to draw inferences comparing the various agents’ influ-
ence in relation to each other and compared to the agents’ or
their corporate sponsors’ political activity and contributions to
either the President or key members of Congress. In short, we
find the public interest in “government openness that would
be served by disclosure” of how the government makes deci-
sions potentially shielding firms lobbying (and donating to
campaigns) from nine-figure liabilities to be plainly impor-
tant. See 

.

   [12] The district court also correctly found that lobbyists’
privacy interests in the nature of their employment, should not
counterbalance the public’s strong interest. See Sims v. CIA,

, 574-75 (D.C. Cir. 1980); People for the Am.
Way 

. Putting aside the
national security concerns discussed above, as we must under
Exemption 6, government acknowledgment of a lobbyist’s
lobbying activities does not reveal “sensitive personal infor-
mation” about the individual rising to a “clearly unwarranted
invasion of personal privacy.” Judicial Watch, Inc. v. Dep’t of
Justice, 

, 1126 (D.C. Cir. 2004); Reed v. NLRB,
                          EFF v. ODNI                        2335

, 1251 (D.C. Cir. 1991). “Official information
that sheds light on an agency’s performance of its statutory
duties falls squarely within [Exemption 6’s] statutory pur-
pose.” Reporters 

. Unlike situations
in which private citizens find themselves in a large govern-
ment database because of conduct unrelated to the inquiry
underlying the FOIA action, when “[t]he applicant is petition-
ing the government for the performance of a public act; this
is not a situation where he is a third-party who finds himself
in government records through no action of his own.” Lard-
ner, 

at *17.

    [13] With regard to the carriers’ agents’ email addresses,
however, the district court did not perform the same careful
balancing in which it engaged for the agents’ names. As EFF
explained, the public interest in disclosing the identities of the
lobbyists’ names is to shed light on which companies and
which individuals influence government decision making. We
agree with that rationale, but we find no corresponding inter-
est as to the carriers’ agents’ email addresses. Yet we can eas-
ily envision possible privacy invasions resulting from public
disclosure of the email addresses. EFF provides no argument,
and we can think of none, countering our conclusion that the
email addresses may add to the risk of privacy invasion with
little additional benefit to the public interest. See Forest Serv.
Employees for Envtl. Ethics v. U.S. Forest Serv., 

, 1025 (9th Cir. 2008) (“[I]nformation about private citi-
zens that is accumulated in various governmental files but that
reveals little or nothing about an agency’s own conduct is not
the type of information to which FOIA permits access.”)
(internal quotation marks omitted).

   [14] Thus the carriers’ agents’ email addresses, when not
needed to identify the party communicating with the govern-
ment, are protected from release by Exemption 6. If, however,
a particular email address is the only way to identify the carri-
ers’ agent at issue from the disputed records, such information
is not properly withheld under Exemption 6 because this
2336                     EFF v. ODNI
minor privacy interest does not counterbalance the robust
interest of citizens’ right to know “what their government is
up to.” Reporters 

(internal quotation
marks omitted).

   [15] In short, we affirm the district court’s careful balanc-
ing of the public interest against the privacy interests of
agents for the carriers, finding disclosure of the names of peo-
ple seeking to influence the agencies’ pursuit of a retroactive
carrier shield does not constitute “a clearly unwarranted inva-
sion of personal privacy.” 5 U.S.C. § 552(b)(6) (2006). How-
ever, we reverse the district court as to the agents’ email
addresses—so long as they are not needed to identify the
agent—for which there is little public interest in disclosure
and at least some privacy interest.

C.     Information Excluded Under Exemption 5

   The parties also dispute the propriety of the government
withholding information, primarily in emails, pursuant to
FOIA Exemption 5. Exemption 5 provides that FOIA “does
not apply to matters that are . . . inter-agency or intra-agency
memorandums or letters which would not be available by law
to a party other than an agency in litigation with the agency.”

   In the district court, the government attempted to withhold
communications regarding the FISA Amendments between
the Executive Branch, Congress, and the telecommunications
firms under Exemption 5. As the district court explained, “the
bulk of the records at issue consist[ed] of confidential email
messages exchanged between ODNI or DOJ official[s] and
congressional staff in which the parties to the emails dis-
cussed, analyzed and negotiated possible amendments to
FISA.” The district court found the government had improp-
erly withheld documents under Exemption 5 and ordered the
disclosure of all disputed documents, including all
“documents exchanged between ODNI and DOJ officials and
                        EFF v. ODNI                       2337
congressional staff or those documents regarding communica-
tions between representatives of the telecommunications com-
panies and government officials.”

   Unlike more thorough district court opinions in compli-
cated FOIA cases specifying groups of documents to disclose
according to the government’s Vaughn indices, see, e.g., Peo-
ple for the Am. Way 

(ana-
lyzing each category of withheld documents in detail), the
district court here ordered complete disclosure of all disputed
documents without focusing on information in the Vaughn
indices showing distribution only within the DOJ and ODNI
or between the DOJ and the White House.

   On appeal, defendants concede that subsequent to the dis-
trict court order, the government determined the district court
was correct to order disclosure of the documents exchanged
between the Executive Branch and Congress, as well as those
in which the telecommunications firms were involved in the
exchange. See Dep’t of the Interior v. Klamath Water Users
Protective Ass’n, 

, 8 (2001). The government thus
released these documents per the district court order, redact-
ing information identifying telecommunications firms or their
agents pursuant to the Exemption 3 and Exemption 6 issues
discussed above. However, the government essentially takes
issue with the thoroughness of the district court, noting its
broad order includes categories of information from the
Vaughn indices circulated only within executive agencies and
the White House.

   EFF focuses on arguments regarding whether the Executive
Office of the President is an “agency,” and how we should
address the privilege claims if we find the district court
improperly concluded all documents were not inter-branch or
intra-branch communications. Presumably EFF focuses on
these arguments because, in passing, it concedes the district
court erred in finding all documents at issue were not inter-
branch or intra-branch memorandums or letters. EFF notes,
2338                          EFF v. ODNI
“[t]he government argues, and EFF agrees, that communica-
tions within DOJ and ODNI or between Executive Branch
agencies satisfy the threshold.”

  This explanation highlights the district court’s error and
demonstrates why remand on Exemption 5 is necessary.
While a district court’s broad rejection of an Exemption 5
withholding is not necessarily problematic, its inquiry should
be fact-specific, and, as demonstrated below, the absence of
a careful review of the record in this case warrants remand.

   [16] To qualify for Exemption 5’s protection from disclo-
sure, “a document must . . . satisfy two conditions: its source
must be a Government agency, and it must fall within the
ambit of a privilege against discovery under judicial standards
that would govern litigation against the agency that holds it.”

.

   The government primarily challenges the district court’s
finding that none of the still-disputed documents are “inter-
agency or intra-agency memorandums or letters.” See 5
U.S.C. § 552(b)(5). In support of its argument, the govern-
ment partially undertakes the exercise that the district court
should have engaged to reach its decision: the government
looks to specific entries in the Vaughn indices and declara-
tions, arguing they are inter-agency or intra-agency docu-
ments. Specifically, the government points to a number of
documents which it convincingly argues the district court
improperly found were not inter-agency or intra-agency mem-
orandums or letters.4
  4
    Relying on the declaration of Melanie Ann Pustay, Director of the
Office of Information and Privacy (“OIP”), U.S. DOJ, the government
cites the following documents:
      1.   OIP Vaughn Index categories 1, 2, 3, and 9, which are “con-
           fidential communications exchanged within the Executive
           Branch or between offices within the Department of Justice
           discussing options, forwarding draft language, and exchang-
           ing ideas regarding FISA amendments.”
                             EFF v. ODNI                            2339
  [17] Examining the Vaughn indices themselves shows the
importance of engaging in the admittedly time-consuming
analysis not performed here. Nearly all of the characteriza-

    2.   OIP Vaughn Index category 4, which “contains draft memo-
         randa, notes, and talking points regarding amendments to the
         FISA.”
    3.   OIP Vaughn Index categories 3 and 9, which include deliber-
         ative emails exchanged within DOJ.
    4.   OIP Vaughn Index categories 1 and 2, which include deliber-
         ative emails exchanged between DOJ and other Executive
         Branch and White House officials.
  Relying on the declaration of Charles Steele, Chief of Staff of DOJ’s
National Security Division, the government cites the following document:
    1.   NSD Vaughn Index groups 2 and 3, which are “communica-
         tions exchanged within the Executive Branch or offices
         within the Department of Justice.”
 Relying on the declaration of Paul Colborn, Special Counsel in the
OLC, the government cites the following documents:
    1.   OLC Vaughn Index numbers 4, 9, 112, 114, and 115, which
         “consist of internal Executive Branch e-mail deliberations
         regarding communications . . . concerning FISA.”
    2.   OLC Vaughn Index numbers 46 and 74, which are “intra
         Executive Branch e-mails discussing the substance of com-
         munications with counsel for the telecommunications com-
         panies sharing a common interest with the United States.”
    3.   20 emails, for which the Vaughn Index numbers are not spec-
         ified, “exchanged between OLC attorneys and other Depart-
         ment of Executive Branch staff.”
  Relying on the declaration of John Hackett, Director of the Information
Management Office for the ODNI, the government cites the following
document:
    1.   ODNI Vaughn Index category 5, which is an “email chain”
         ”between ODNI and NSA officials.”
  This list may not be entirely exhaustive, but it is a powerful example
of documents that, according to the relevant Vaughn index, were
exchanged within the Executive Branch or between agencies.
2340                         EFF v. ODNI
tions in the government-offered declarations comport with the
descriptions in the Vaughn indices of inter-branch or intra-
branch communications. Thus, for these emails, the district
court should have more closely examined the documents to
determine whether they were in fact inter-agency or intra-
agency memorandums or letters. Including them in a broad
disclosure order was error under any standard.

   In addition, in at least two instances (OLC Vaughn Index
numbers 46 & 74), the plain language of the declaration
seems to imply an intra-Executive Branch email when, in fact,
the Vaughn Index makes clear the communications at issue
were between the Executive Branch and telecommunications
company representatives. This highlights the need for a fact-
specific inquiry under Exemption 5.

   Thus the district court’s blanket finding that all of the dis-
puted communications were not inter-branch or intra-branch
memorandums or letters eligible for privilege analysis under
Exemption 5 is problematic, as is clear from the face of the
government’s declarations and Vaughn indices.5 This may
have occurred because the documents in question were
included with so many other documents exchanged between
the Executive Branch and either Congress or the telecommu-
nications carriers, as to which the district court correctly con-
cluded Exemption 5 did not apply.

  [18] Accordingly, we remand to the district court on
Exemption 5 to examine each contested category of docu-
ments to determine whether its actual sender(s) and recipi-
ent(s) render it an inter-agency or intra-agency document,
  5
    This is not to say the district court must find all of these documents
inter-agency or intra-agency memorandums or letters on remand. How-
ever, it should examine the Vaughn indices and declarations, and conduct
an in camera examination of the actual documents if necessary, to deter-
mine exactly who in the government was transmitting and receiving the
information and whether Exemption 5 thus applies (in which case the dis-
trict court would have to consider if the information was privileged).
                           EFF v. ODNI                     2341
keeping in mind the contours of the doctrine concerning
whether the Executive Office of the President and certain
other White House components are “agencies” for FOIA pur-
poses. See, e.g., 5 U.S.C. § 552(f)(1) (2006) (“ ‘[A]gency’ as
defined in section 551(1) of this title includes any executive
department, military department, Government corporation,
Government controlled corporation, or other establishment in
the executive branch of the Government (including the Execu-
tive Office of the President.)”); Kissinger v. Reporters Comm.
for Freedom of the Press, 

, 156 (1980); Judicial
Watch 

. For those documents the dis-
trict court classifies as inter-agency or intra-agency, the dis-
trict court will then have to consider whether any of the
government’s asserted privileges allow withholding. See

.

                    III.   CONCLUSION

   [19] We affirm the district court’s grant of summary judg-
ment for EFF as to the release of names and email addresses
under FOIA Exemption 6, though we reverse as to email
addresses only for which other information identifying the
agent at issue is available in the communication. This order
may not necessarily result in disclosure of names for which
the government also argues withholding pursuant to Exemp-
tion 3, because we vacate the district court’s denial of sum-
mary judgment for the government and grant of summary
judgment for EFF as to FOIA Exemptions 3 and 5, and
remand for consideration of these Exemptions consistent with
this Opinion.

  AFFIRMED in part, REVERSED in part, VACATED
and REMANDED in part. Each party shall bear its own
costs on appeal.