(Slip Opinion)              OCTOBER TERM, 2008                                       1

                                       Syllabus

         NOTE: Where it is feasible, a syllabus (headnote) will be released, as is
       being done in connection with this case, at the time the opinion is issued.
       The syllabus constitutes no part of the opinion of the Court but has been
       prepared by the Reporter of Decisions for the convenience of the reader.
       See United States v. Detroit Timber & Lumber Co., 

, 337.


SUPREME COURT OF THE UNITED STATES

                                       Syllabus

 CRAWFORD v. METROPOLITAN GOVERNMENT OF
 NASHVILLE AND DAVIDSON COUNTY, TENNESSEE

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR
                  THE SIXTH CIRCUIT

   No. 06–1595. Argued October 8, 2008—Decided January 26, 2009
In response to questions from an official of respondent local government
  (Metro) during an internal investigation into rumors of sexual har
  assment by the Metro School District employee relations director
  (Hughes), petitioner Crawford, a 30-year employee, reported that
  Hughes had sexually harassed her. Metro took no action against
  Hughes, but soon fired Crawford, alleging embezzlement. She filed
  suit under Title VII of the Civil Rights Act of 1964, claiming that
  Metro was retaliating for her report of Hughes’s behavior, in violation
  of 

. §2000e–3(a), which makes it unlawful “for an employer
  to discriminate against any . . . employe[e]” who (1) “has opposed any
  practice made an unlawful employment practice by this subchapter”
  (opposition clause), or (2) “has made a charge, testified, assisted, or
  participated in any manner in an investigation, proceeding, or hear
  ing under this subchapter” (participation clause). The court granted
  Metro summary judgment, and the Sixth Circuit affirmed, holding
  that the opposition clause demanded “active, consistent” opposing ac
  tivities, whereas Crawford had not initiated any complaint prior to
  the investigation, and finding that the participation clause did not
  cover Metro’s internal investigation because it was not conducted
  pursuant to a Title VII charge pending with the Equal Employment
  Opportunity Commission.
Held: The antiretaliation provision’s protection extends to an employee
 who speaks out about discrimination not on her own initiative, but in
 answering questions during an employer’s internal investigation.
 Because “oppose” is undefined by statute, it carries its ordinary dic
 tionary meaning of resisting or contending against. Crawford’s
 statement is thus covered by the opposition clause, as an ostensibly
2         CRAWFORD v. METROPOLITAN GOVERNMENT OF 

               NASHVILLE AND DAVIDSON CTY. 

                          Syllabus 


    disapproving account of Hughes’s sexually obnoxious behavior toward
    her. “Oppose” goes beyond “active, consistent” behavior in ordinary
    discourse, and may be used to speak of someone who has taken no ac
    tion at all to advance a position beyond disclosing it. Thus, a person
    can “oppose” by responding to someone else’s questions just as surely
    as by provoking the discussion. Nothing in the statute requires a
    freakish rule protecting an employee who reports discrimination on
    her own initiative but not one who reports the same discrimination in
    the same words when asked a question. Metro unconvincingly ar
    gues for the Sixth Circuit’s active, consistent opposition rule, claim
    ing that employers will be less likely to raise questions about possible
    discrimination if a retaliation charge is easy to raise when things go
    badly for an employee who responded to enquiries. Employers, how
    ever, have a strong inducement to ferret out and put a stop to dis
    criminatory activity in their operations because Burlington Indus
    tries, Inc. v. Ellerth, 

, 765, and Faragher v. Boca Raton,
    

, 807, hold “[a]n employer . . . subject to vicarious liabil
    ity to a victimized employee for an actionable hostile environment
    created by a supervisor with . . . authority over the employee.” The
    Circuit’s rule could undermine the Ellerth-Faragher scheme, along
    with the statute’s “ ‘primary objective’ ” of “avoid[ing] harm” to em
    ployees, 

, for if an employee reporting dis
    crimination in answer to an employer’s questions could be penalized
    with no remedy, prudent employees would have a good reason to keep
    quiet about Title VII offenses. Because Crawford’s conduct is covered
    by the opposition clause, this Court does not reach her argument that
    the Sixth Circuit also misread the participation clause. Metro’s other
    defenses to the retaliation claim were never reached by the District
    Court, and thus remain open on remand. Pp. 3–8.
211 Fed. Appx. 373, reversed and remanded.

   SOUTER, J., delivered the opinion of the Court, in which ROBERTS,
C. J., and STEVENS, SCALIA, KENNEDY, GINSBURG, and BREYER, JJ.,
joined. ALITO, J., filed an opinion concurring in the judgment, in which
THOMAS, J., joined.
                        Cite as: 555 U. S. ____ (2009)                              1

                             Opinion of the Court

     NOTICE: This opinion is subject to formal revision before publication in the
     preliminary print of the United States Reports. Readers are requested to
     notify the Reporter of Decisions, Supreme Court of the United States, Wash
     ington, D. C. 20543, of any typographical or other formal errors, in order
     that corrections may be made before the preliminary print goes to press.


SUPREME COURT OF THE UNITED STATES
                                   _________________

                                   No. 06–1595
                                   _________________


    VICKY S. CRAWFORD, PETITIONER v. METRO-

      POLITAN GOVERNMENT OF NASHVILLE 

       AND DAVIDSON COUNTY, TENNESSEE

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE SIXTH CIRCUIT

                               [January 26, 2009] 


  JUSTICE SOUTER delivered the opinion of the Court.
  Title VII of the Civil Rights Act of 1964, 78 Stat. 253, as
amended, 

. §2000e et seq. (2000 ed. and Supp.
V), forbids retaliation by employers against employees
who report workplace race or gender discrimination. The
question here is whether this protection extends to an
employee who speaks out about discrimination not on her
own initiative, but in answering questions during an
employer’s internal investigation. We hold that it does.
                           I
  In 2002, respondent Metropolitan Government of                               Nash
ville and Davidson County, Tennessee (Metro),                                  began
looking into rumors of sexual harassment by the                                Metro
School District’s employee relations director,                                  Gene
Hughes.1 211 Fed. Appx. 373, 374 (CA6 2006).                                   When

——————
  1 Because this case arises out of the District Court’s grant of sum
mary judgment for Metro, “we are required to view all facts and draw
all reasonable inferences in favor of the nonmoving party, [Crawford].”
Brosseau v. Haugen, 

, 195, n. 2 (2004) (per curiam).
2      CRAWFORD v. METROPOLITAN GOVERNMENT OF 

            NASHVILLE AND DAVIDSON CTY. 

                    Opinion of the Court 


Veronica Frazier, a Metro human resources officer, asked
petitioner Vicky Crawford, a 30-year Metro employee,
whether she had witnessed “inappropriate behavior” on
the part of Hughes, 

Crawford described
several instances of sexually harassing behavior: once,
Hughes had answered her greeting, “ ‘Hey Dr. Hughes,
what’s up?,’ ” by grabbing his crotch and saying “ ‘[Y]ou
know what’s up’ ”; he had repeatedly “ ‘put his crotch up to
[her] window’ ”; and on one occasion he had entered her
office and “ ‘grabbed her head and pulled it to his crotch,’ ”

and n. 1. Two other employees also reported
being sexually harassed by Hughes. 

Although
Metro took no action against Hughes, it did fire Crawford
and the two other accusers soon after finishing the inves
tigation, saying in Crawford’s case that it was for embez
zlement. 

was retaliating
for her report of Hughes’s behavior and filed a charge of a
Title VII violation with the Equal Employment Opportu
nity Commission (EEOC), followed by this suit in the
United States District Court for the Middle District of
Tennessee. 

antiretaliation provision has two clauses,
making it “an unlawful employment practice for an em
ployer to discriminate against any of his employees . . . [1]
because he has opposed any practice made an unlawful
employment practice by this subchapter, or [2] because he
has made a charge, testified, assisted, or participated in
any manner in an investigation, proceeding, or hearing
under this subchapter.” 

. §2000e–3(a). The one
is known as the “opposition clause,” the other as the “par
ticipation clause,” and Crawford accused Metro of violat
ing both.
   The District Court granted summary judgment for
Metro. It held that Crawford could not satisfy the opposi
tion clause because she had not “instigated or initiated
any complaint,” but had “merely answered questions by
                 Cite as: 555 U. S. ____ (2009)            3

                     Opinion of the Court

investigators in an already-pending internal investigation,
initiated by someone else.” Memorandum Opinion, No.
3:03–cv–00996 (MD Tenn., Jan. 6, 2005), App. C to Pet. for
Cert. 16a–17a. It concluded that her claim also failed
under the participation clause, which Sixth Circuit prece
dent confined to protecting “ ‘an employee’s participation
in an employer’s internal investigation . . . where that
investigation occurs pursuant to a pending EEOC charge’ ”
(not the case here). 

(emphasis omitted) (quot
ing Abbott v. Crown Motor Co., 

, 543 (CA6
2003)).
  The Court of Appeals affirmed on the same grounds,
holding that the opposition clause “ ‘demands active, con
sistent “opposing” activities to warrant . . . protection
against retaliation,’ ” 211 Fed. Appx., at 376 (quoting Bell
v. Safety Grooving & Grinding, LP, 107 Fed. Appx. 607,
610 (CA6 2004)), whereas Crawford did “not claim to have
instigated or initiated any complaint prior to her partici
pation in the investigation, nor did she take any further
action following the investigation and prior to her firing.”
211 Fed. Appx., at 376. Again like the trial judge, the
Court of Appeals understood that Crawford could show no
violation of the participation clause because her “ ‘em
ployer’s internal investigation’ ” was not conducted “ ‘pur
suant to a pending EEOC charge.’ ” 

at 543).
  Because the Sixth Circuit’s decision conflicts with those
of other Circuits, particularly as to the opposition clause,
see, e.g., McDonnell v. Cisneros, 

, 262 (CA7
1996), we granted Crawford’s petition for certiorari. 552
U. S. ___ (2008). We now reverse and remand for further
proceedings.
                          II
  The opposition clause makes it “unlawful . . . for an
employer to discriminate against any . . . employe[e] . . .
4     CRAWFORD v. METROPOLITAN GOVERNMENT OF 

           NASHVILLE AND DAVIDSON CTY. 

                   Opinion of the Court 


because he has opposed any practice made . . . unlawful
. . . by this subchapter.” §2000e–3(a). The term “oppose,”
being left undefined by the statute, carries its ordinary
meaning, Perrin v. United States, 

, 42 (1979):
“to resist or antagonize . . . ; to contend against; to con
front; resist; withstand,” Webster’s New International
Dictionary 1710 (2d ed. 1958). Although these actions
entail varying expenditures of energy, “RESIST frequently
implies more active striving than OPPOSE.” Ibid.; see also
Random House Dictionary of the English Language 1359
(2d ed. 1987) (defining “oppose” as “to be hostile or adverse
to, as in opinion”).
    The statement Crawford says she gave to Frazier is thus
covered by the opposition clause, as an ostensibly disap
proving account of sexually obnoxious behavior toward her
by a fellow employee, an answer she says antagonized her
employer to the point of sacking her on a false pretense.
Crawford’s description of the louche goings-on would
certainly qualify in the minds of reasonable jurors as
“resist[ant]” or “antagoni[stic]” to Hughes’s treatment, if
for no other reason than the point argued by the Govern
ment and explained by an EEOC guideline: “When an
employee communicates to her employer a belief that the
employer has engaged in . . . a form of employment dis
crimination, that communication” virtually always “consti
tutes the employee’s opposition to the activity.” Brief for
United States as Amicus Curiae 9 (citing 2 EEOC Compli
ance Manual §§8–II–B(1), (2), p. 614:0003 (Mar. 2003));
see also Federal Express Corp. v. Holowecki, 552 U. S. ___,
___ (2008) (slip op., at 8) (explaining that EEOC compli
ance manuals “reflect ‘a body of experience and informed
judgment to which courts and litigants may properly
resort for guidance’ ” (quoting Bragdon v. Abbott, 

, 642 (1998))). It is true that one can imagine excep
tions, like an employee’s description of a supervisor’s
racist joke as hilarious, but these will be eccentric cases,
                     Cite as: 555 U. S. ____ (2009)                    5

                          Opinion of the Court

and this is not one of them.2
   The Sixth Circuit thought answering questions fell short
of opposition, taking the view that the clause “ ‘demands
active, consistent “opposing” activities to warrant . . .
protection against retaliation,’ ” 211 Fed. Appx., at 376
(quoting 

), and that an employee must
“instigat[e] or initiat[e]” a complaint to be covered, 211
Fed. Appx., at 376. But though these requirements obvi
ously exemplify opposition as commonly understood, they
are not limits of it.
   “Oppose” goes beyond “active, consistent” behavior in
ordinary discourse, where we would naturally use the
word to speak of someone who has taken no action at all to
advance a position beyond disclosing it. Countless people
were known to “oppose” slavery before Emancipation, or
are said to “oppose” capital punishment today, without
writing public letters, taking to the streets, or resisting
the government. And we would call it “opposition” if an
employee took a stand against an employer’s discrimina
tory practices not by “instigating” action, but by standing
pat, say, by refusing to follow a supervisor’s order to fire a
junior worker for discriminatory reasons. Cf. 

(finding employee covered by Title VII of the
Civil Rights Act of 1964 where his employer retaliated
against him for failing to prevent his subordinate from
filing an EEOC charge). There is, then, no reason to doubt
that a person can “oppose” by responding to someone else’s

——————
   2 Metro suggests in passing that it was unclear whether Crawford

actually opposed Hughes’s behavior because some of her defensive
responses were “inappropriate,” such as telling Hughes to “bite me” and
“flip[ping] him a bird.” Brief for Respondent 1–2 (internal quotation
marks omitted). This argument fails not only because at the summary
judgment stage we must “view all facts and draw all reasonable infer
ences in [Crawford’s] favor,” 

, n. 2, but also
because Crawford gave no indication that Hughes’s gross clowning was
anything but offensive to her.
6      CRAWFORD v. METROPOLITAN GOVERNMENT OF 

            NASHVILLE AND DAVIDSON CTY. 

                    Opinion of the Court 


question just as surely as by provoking the discussion, and
nothing in the statute requires a freakish rule protecting
an employee who reports discrimination on her own initia
tive but not one who reports the same discrimination in
the same words when her boss asks a question.
   Metro and its amici support the Circuit panel’s insis
tence on “active” and “consistent” opposition by arguing
that the lower the bar for retaliation claims, the less likely
it is that employers will look into what may be happening
outside the executive suite. As they see it, if retaliation
is an easy charge when things go bad for an employee
who responded to enquiries, employers will avoid the
headache by refusing to raise questions about possible
discrimination.
   The argument is unconvincing, for we think it underes
timates the incentive to enquire that follows from our
decisions in Burlington Industries, Inc. v. Ellerth, 

(1998), and Faragher v. Boca Raton, 

(1998). Ellerth and Faragher hold “[a]n employer . . .
subject to vicarious liability to a victimized employee for
an actionable hostile environment created by a supervisor
with . . . authority over the employee.” 

; 

. Although there is no af
firmative defense if the hostile environment “culminates
in a tangible employment action” against the employee,

, an employer does have a defense
“[w]hen no tangible employment action is taken” if it
“exercised reasonable care to prevent and correct promptly
any” discriminatory conduct and “the plaintiff employee
unreasonably failed to take advantage of any preventive or
corrective opportunities provided by the employer or to
avoid harm otherwise,” 

subject
to a strong inducement to ferret out and put a stop to any
discriminatory activity in their operations as a way to
break the circuit of imputed liability. Ibid.; see also Brief
for Petitioner 24–28, and nn. 31–35 (citing studies demon
                 Cite as: 555 U. S. ____ (2009)            7

                     Opinion of the Court

strating that Ellerth and Faragher have prompted many
employers to adopt or strengthen procedures for investi
gating, preventing, and correcting discriminatory con
duct). The possibility that an employer might someday
want to fire someone who might charge discrimination
traceable to an internal investigation does not strike us as
likely to diminish the attraction of an Ellerth-Faragher
affirmative defense.
   That aside, we find it hard to see why the Sixth Circuit’s
rule would not itself largely undermine the Ellerth-
Faragher scheme, along with the statute’s “ ‘primary objec
tive’ ” of “avoid[ing] harm” to employees. 

(quoting Albemarle Paper Co. v. Moody, 

, 417 (1975)). If it were clear law that an employee
who reported discrimination in answering an employer’s
questions could be penalized with no remedy, prudent
employees would have a good reason to keep quiet about
Title VII offenses against themselves or against others.
This is no imaginary horrible given the documented indi
cations that “[f]ear of retaliation is the leading reason why
people stay silent instead of voicing their concerns about
bias and discrimination.” Brake, Retaliation, 

. Rev. 18, 20 (2005); see also 

and n. 58 (compil
ing studies). The appeals court’s rule would thus create a
real dilemma for any knowledgeable employee in a hostile
work environment if the boss took steps to assure a de
fense under our cases. If the employee reported discrimi
nation in response to the enquiries, the employer might
well be free to penalize her for speaking up. But if she
kept quiet about the discrimination and later filed a Title
VII claim, the employer might well escape liability, argu
ing that it “exercised reasonable care to prevent and cor
rect [any discrimination] promptly” but “the plaintiff
employee unreasonably failed to take advantage of . . .
preventive or corrective opportunities provided by the
employer.” 

. Nothing in the statute’s
8       CRAWFORD v. METROPOLITAN GOVERNMENT OF 

             NASHVILLE AND DAVIDSON CTY. 

                     Opinion of the Court 


text or our precedent supports this catch-22.3
   Because Crawford’s conduct is covered by the opposition
clause, we do not reach her argument that the Sixth Cir
cuit misread the participation clause as well. But that
does not mean the end of this case, for Metro’s motion for
summary judgment raised several defenses to the retalia
tion charge besides the scope of the two clauses; the Dis
trict Court never reached these others owing to its ruling
on the elements of retaliation, and they remain open on
remand.
                            III
  The judgment of the Court of Appeals for the Sixth
Circuit is reversed, and the case is remanded for further
proceedings consistent with this opinion.
                                          It is so ordered.



——————
  3 Metro also argues that “[r]equiring the employee to actually initiate

a complaint . . . conforms with the employee’s ‘obligation of reasonable
care to avoid harm’ articulated in Faragher and Ellerth.” Brief for
Respondent 28 (quoting Faragher v. Boca Raton, 

, 807
(1998)). But that mitigation requirement only applies to employees
who are suffering discrimination and have the opportunity to fix it by
“tak[ing] advantage of any preventive or corrective opportunities
provided by the employer,” ibid.; it is based on the general principle
“that a victim has a duty ‘to use such means as are reasonable under
the circumstances to avoid or minimize . . . damages,’ ” 

(quoting Ford Motor Co. v. EEOC, 

, 231, n. 15 (1982)). We
have never suggested that employees have a legal obligation to report
discrimination against others to their employer on their own initiative,
let alone lose statutory protection by failing to speak. Extending the
mitigation requirement so far would make no sense; employees will
often face retaliation not for opposing discrimination they themselves
face, but for reporting discrimination suffered by others. Thus, they are
not “victims” of anything until they are retaliated against, and it would
be absurd to require them to “mitigate” damages they may be unaware
they will suffer.
                 Cite as: 555 U. S. ____ (2009)           1

                ALITO, J., concurring in judgment

SUPREME COURT OF THE UNITED STATES
                          _________________

                          No. 06–1595
                          _________________


    VICKY S. CRAWFORD, PETITIONER v. METRO-

      POLITAN GOVERNMENT OF NASHVILLE 

       AND DAVIDSON COUNTY, TENNESSEE

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

            APPEALS FOR THE SIXTH CIRCUIT

                       [January 26, 2009] 


  JUSTICE ALITO, with whom JUSTICE THOMAS joins,
concurring in the judgment.
  The question in this case is whether Title VII of the
Civil Rights Act of 1964, 78 Stat. 253, as amended, 

. §2000e et seq. (2000 ed. and Supp. V), prohibits
retaliation against an employee who testifies in an inter
nal investigation of alleged sexual harassment. I agree
with the Court that the “opposition clause” of §2000e–3(a)
(2000 ed.) prohibits retaliation for such conduct. I also
agree with the Court’s primary reasoning, which is based
on “the point argued by the Government and explained by
an EEOC guideline: ‘When an employee communicates to
her employer a belief that the employer has engaged in . . .
a form of employment discrimination, that communication’
virtually always ‘constitutes the employee’s opposition to
the activity.’ ” Ante, at 4. I write separately to emphasize
my understanding that the Court’s holding does not
and should not extend beyond employees who testify in
internal investigations or engage in analogous purposive
conduct.
  As the Court concludes, the term “oppose” does not
denote conduct that necessarily rises to the level required
by the Sixth Circuit—i.e., conduct that is “ ‘consistent’ ”
and “instigated or initiated” by the employee. 211 Fed.
2      CRAWFORD v. METROPOLITAN GOVERNMENT OF 

            NASHVILLE AND DAVIDSON CTY. 

              ALITO, J., concurring in judgment


Appx. 373, 376 (2006). The primary definitions of the
term “oppose” do, however, require conduct that is active
and purposive. See Webster’s New International Diction
ary 1709–1710 (2d ed. 1953); Random House Dictionary of
the English Language 1010 (1966) (hereinafter Random
Dict.); 10 Oxford English Dictionary 866–867 (2d ed.
1989). For example, the first three definitions of the term
in the dictionary upon which the Court principally relies
are as follows:
    “1. to act against or provide resistance to; combat. 2.
    to stand in the way of; hinder; obstruct. 3. to set as an
    opponent or adversary.” Random Dict. 1359 (2d ed.
    1987).
In accordance with these definitions, petitioner contends
that the statutory term “oppose” means “taking action
(including making a statement) to end, prevent, redress,
or correct unlawful discrimination.” Brief for Petitioner
40.
   In order to decide the question that is before us, we have
no need to adopt a definition of the term “oppose” that is
broader than the definition that petitioner advances. But
in dicta, the Court notes that the fourth listed definition in
the Random House Dictionary of the English Language
goes further, defining “oppose” to mean “ ‘to be hostile or
adverse to, as in opinion.’ ” Ante, at 4 (emphasis added).
Thus, this definition embraces silent opposition.
   While this is certainly an accepted usage of the term
“oppose,” the term is not always used in this sense, and it
is questionable whether silent opposition is covered by the
opposition clause of 

. §2000e–3(a). It is notewor
thy that all of the other conduct protected by this provi
sion—making a charge, testifying, or assisting or partici
pating in an investigation, proceeding, or hearing—
requires active and purposive conduct. “ ‘That several
items in a list share an attribute counsels in favor of
                 Cite as: 555 U. S. ____ (2009)            3

                ALITO, J., concurring in judgment

interpreting the other items as possessing that attribute
as well.’ ” S. D. Warren Co. v. Maine Bd. of Environmental
Protection, 

, 378 (2006) (quoting Beecham v.
United States, 

, 371 (1994)).
   An interpretation of the opposition clause that protects
conduct that is not active and purposive would have im
portant practical implications. It would open the door to
retaliation claims by employees who never expressed a
word of opposition to their employers. To be sure, in many
cases, such employees would not be able to show that
management was aware of their opposition and thus
would not be able to show that their opposition caused the
adverse actions at issue. But in other cases, such employ
ees might well be able to create a genuine factual issue on
the question of causation. Suppose, for example, that an
employee alleges that he or she expressed opposition while
informally chatting with a co-worker at the proverbial
water cooler or in a workplace telephone conversation that
was overheard by a co-worker. Or suppose that an em
ployee alleges that such a conversation occurred after
work at a restaurant or tavern frequented by co-workers
or at a neighborhood picnic attended by a friend or relative
of a supervisor.
   Some courts hold that an employee asserting a retalia
tion claim can prove causation simply by showing that the
adverse employment action occurred within a short time
after the protected conduct. See, e.g., Clark County School
Dist. v. Breeden, 

, 273 (2001) (per curiam)
(noting that some cases “accept mere temporal proximity
between an employer’s knowledge of protected activity and
an adverse employment action as sufficient evidence of
causality to establish a prima facie case”); see also
Gorman-Bakos v. Cornell Cooperative Extension of
Schenectady Cty., 

, 554 (CA2 2001); Conner
v. Schnuk Markets, Inc., 

, 1395 (CA10
1997); Dey v. Colt Constr. & Dev. Co., 

, 1458
4     CRAWFORD v. METROPOLITAN GOVERNMENT OF 

           NASHVILLE AND DAVIDSON CTY. 

             ALITO, J., concurring in judgment


(CA7 1994). As a result, an employee claiming retaliation
may be able to establish causation simply by showing that,
within some time period prior to the adverse action, the
employer, by some indirect means, became aware of the
views that the employee had expressed. Where the pro
tected conduct consisted of a private conversation, applica
tion of this rule would be especially problematic because of
uncertainty regarding the point in time when the em
ployer became aware of the employee’s private expressions
of disapproval.
   The number of retaliation claims filed with the EEOC
has proliferated in recent years. See U. S. Equal Em
ployment Opportunity Commission, Charge Statistics:
FY 1997 Through FY 2007, http://www.eeoc.gov/stats/
charges.html; Charge Statistics: FY 1992 Through FY
1996, http://www.eeoc.gov/stats/charges-a.html (as visited
Jan. 16, 2009, and available in Clerk of Court’s case file)
(showing that retaliation charges filed with the EEOC
doubled between 1992 and 2007). An expansive interpre
tation of protected opposition conduct would likely cause
this trend to accelerate.
   The question whether the opposition clause shields
employees who do not communicate their views to their
employers through purposive conduct is not before us in
this case; the answer to that question is far from clear;
and I do not understand the Court’s holding to reach that
issue here. For present purposes, it is enough to hold that
the opposition clause does protect an employee, like peti
tioner, who testifies about unlawful conduct in an internal
investigation.