(Slip Opinion)              OCTOBER TERM, 2009                                       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., 200 U. S. 321, 337.


SUPREME COURT OF THE UNITED STATES

                                       Syllabus

    CITY OF ONTARIO, CALIFORNIA, ET AL. v. QUON 

                      ET AL. 


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

      No. 08–1332. Argued April 19, 2010—Decided June 17, 2010
Petitioner Ontario (hereinafter City) acquired alphanumeric pagers
  able to send and receive text messages. Its contract with its service
  provider, Arch Wireless, provided for a monthly limit on the number
  of characters each pager could send or receive, and specified that us
  age exceeding that number would result in an additional fee. The
  City issued the pagers to respondent Quon and other officers in its
  police department (OPD), also a petitioner here. When Quon and
  others exceeded their monthly character limits for several months
  running, petitioner Scharf, OPD’s chief, sought to determine whether
  the existing limit was too low, i.e., whether the officers had to pay
  fees for sending work-related messages or, conversely, whether the
  overages were for personal messages. After Arch Wireless provided
  transcripts of Quon’s and another employee’s August and September
  2002 text messages, it was discovered that many of Quon’s messages
  were not work related, and some were sexually explicit. Scharf re
  ferred the matter to OPD’s internal affairs division. The investigat
  ing officer used Quon’s work schedule to redact from his transcript
  any messages he sent while off duty, but the transcript showed that
  few of his on-duty messages related to police business. Quon was dis
  ciplined for violating OPD rules.
    He and the other respondents—each of whom had exchanged text
  messages with Quon during August and September—filed this suit,
  alleging, inter alia, that petitioners violated their Fourth Amendment
  rights and the federal Stored Communications Act (SCA) by obtain
  ing and reviewing the transcript of Quon’s pager messages, and that
  Arch Wireless violated the SCA by giving the City the transcript.
  The District Court denied respondents summary judgment on the
2                           ONTARIO v. QUON

                                  Syllabus

    constitutional claims, relying on the plurality opinion in O’Connor v.
    Ortega, 480 U. S. 709, to determine that Quon had a reasonable ex
    pectation of privacy in the content of his messages. Whether the au
    dit was nonetheless reasonable, the court concluded, turned on
    whether Scharf used it for the improper purpose of determining if
    Quon was using his pager to waste time, or for the legitimate purpose
    of determining the efficacy of existing character limits to ensure that
    officers were not paying hidden work-related costs. After the jury
    concluded that Scharf’s intent was legitimate, the court granted peti
    tioners summary judgment on the ground they did not violate the
    Fourth Amendment. The Ninth Circuit reversed. Although it agreed
    that Quon had a reasonable expectation of privacy in his text mes
    sages, the appeals court concluded that the search was not reason
    able even though it was conducted on a legitimate, work-related ra
    tionale. The opinion pointed to a host of means less intrusive than
    the audit that Scharf could have used. The court further concluded
    that Arch Wireless had violated the SCA by giving the City the tran
    script.
Held: Because the search of Quon’s text messages was reasonable, peti
 tioners did not violate respondents’ Fourth Amendment rights, and
 the Ninth Circuit erred by concluding otherwise. Pp. 7–17.
    (a) The Amendment guarantees a person’s privacy, dignity, and se
 curity against arbitrary and invasive governmental acts, without re
 gard to whether the government actor is investigating crime or per
 forming another function. Skinner v. Railway Labor Executives’
 Assn., 489 U. S. 602, 613–614. It applies as well when the govern
 ment acts in its capacity as an employer. Treasury Employees v. Von
 Raab, 489 U. S. 656, 665. The Members of the O’Connor Court dis
 agreed on the proper analytical framework for Fourth Amendment
 claims against government employers. A four-Justice plurality con
 cluded that the correct analysis has two steps. First, because “some
 [government] offices may be so open . . . that no expectation of pri
 vacy is reasonable,” a court must consider “[t]he operational realities
 of the workplace” to determine if an employee’s constitutional rights
 are implicated. 480 U. S., at 718. Second, where an employee has a
 legitimate privacy expectation, an employer’s intrusion on that ex
 pectation “for noninvestigatory, work-related purposes, as well as for
 investigations of work-related misconduct, should be judged by the
 standard of reasonableness under all the circumstances.” Id., at 725–
 726. JUSTICE SCALIA, concurring in the judgment, would have dis
 pensed with the “operational realities” inquiry and concluded “that
 the offices of government employees . . . are [generally] covered by
 Fourth Amendment protections,” id., at 731, but he would also have
 held “that government searches to retrieve work-related materials or
                   Cite as: 560 U. S. ____ (2010)                     3

                              Syllabus

to investigate violations of workplace rules—searches of the sort that
are regarded as reasonable and normal in the private-employer con
text—do not violate the . . . Amendment,” id., at 732. Pp. 7–9.
   (b) Even assuming that Quon had a reasonable expectation of pri
vacy in his text messages, the search was reasonable under both
O’Connor approaches, the plurality’s and JUSTICE SCALIA’s. Pp. 9–17.
     (1) The Court does not resolve the parties’ disagreement over
Quon’s privacy expectation. Prudence counsels caution before the
facts in this case are used to establish far-reaching premises that de
fine the existence, and extent, of privacy expectations of employees
using employer-provided communication devices. Rapid changes in
the dynamics of communication and information transmission are
evident not just in the technology itself but in what society accepts as
proper behavior. At present, it is uncertain how workplace norms,
and the law’s treatment of them, will evolve. Because it is therefore
preferable to dispose of this case on narrower grounds, the Court as
sumes, arguendo, that: (1) Quon had a reasonable privacy expecta
tion; (2) petitioners’ review of the transcript constituted a Fourth
Amendment search; and (3) the principles applicable to a government
employer’s search of an employee’s physical office apply as well in the
electronic sphere. Pp. 9–12.
   (2) Petitioners’ warrantless review of Quon’s pager transcript was
reasonable under the O’Connor plurality’s approach because it was
motivated by a legitimate work-related purpose, and because it was
not excessive in scope. See 480 U. S., at 726. There were “reasonable
grounds for [finding it] necessary for a noninvestigatory work-related
purpose,” ibid., in that Chief Scharf had ordered the audit to deter
mine whether the City’s contractual character limit was sufficient to
meet the City’s needs. It was also “reasonably related to the objec
tives of the search,” ibid., because both the City and OPD had a le
gitimate interest in ensuring that employees were not being forced to
pay out of their own pockets for work-related expenses, or, on the
other hand, that the City was not paying for extensive personal
communications. Reviewing the transcripts was an efficient and ex
pedient way to determine whether either of these factors caused
Quon’s overages. And the review was also not “excessively intrusive.”
Ibid. Although Quon had exceeded his monthly allotment a number
of times, OPD requested transcripts for only August and September
2002 in order to obtain a large enough sample to decide the character
limits’ efficaciousness, and all the messages that Quon sent while off
duty were redacted. And from OPD’s perspective, the fact that Quon
likely had only a limited privacy expectation lessened the risk that
the review would intrude on highly private details of Quon’s life.
Similarly, because the City had a legitimate reason for the search
4                           ONTARIO v. QUON

                                  Syllabus

    and it was not excessively intrusive in light of that justification, the
    search would be “regarded as reasonable and normal in the private
    employer context” and thereby satisfy the approach of JUSTICE
    SCALIA’s concurrence, id., at 732. Conversely, the Ninth Circuit’s
    “least intrusive” means approach was inconsistent with controlling
    precedents. See, e.g., Vernonia School Dist. 47J v. Acton, 515 U. S.
    646, 663. Pp. 12–16.
       (c) Whether the other respondents can have a reasonable expecta
    tion of privacy in their text messages to Quon need not be resolved.
    They argue that because the search was unreasonable as to Quon, it
    was also unreasonable as to them, but they make no corollary argu
    ment that the search, if reasonable as to Quon, could nonetheless be
    unreasonable as to them. Given this litigating position and the
    Court’s conclusion that the search was reasonable as to Quon, these
    other respondents cannot prevail. Pp. 16–17.
529 F. 3d 892, reversed and remanded.

  KENNEDY, J., delivered the opinion of the Court, in which ROBERTS,
C. J., and STEVENS, THOMAS, GINSBURG, BREYER, ALITO, and SOTOMAYOR,
JJ., joined, and in which SCALIA, J., joined except for Part III–A. STE-
VENS, J., filed a concurring opinion. SCALIA, J., filed an opinion concur
ring in part and concurring in the judgment.
                        Cite as: 560 U. S. ____ (2010)                              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. 08–1332
                                   _________________


         CITY OF ONTARIO, CALIFORNIA, ET AL., 

           PETITIONERS v. JEFF QUON ET AL. 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE NINTH CIRCUIT

                                 [June 17, 2010] 


  JUSTICE KENNEDY delivered the opinion of the Court.
  This case involves the assertion by a government em­
ployer of the right, in circumstances to be described, to
read text messages sent and received on a pager the em­
ployer owned and issued to an employee. The employee
contends that the privacy of the messages is protected by
the ban on “unreasonable searches and seizures” found in
the Fourth Amendment to the United States Constitution,
made applicable to the States by the Due Process Clause
of the Fourteenth Amendment.         Mapp v. Ohio, 367
U. S. 643 (1961). Though the case touches issues of far-
reaching significance, the Court concludes it can be re­
solved by settled principles determining when a search is
reasonable.
                                          I
                             A
  The City of Ontario (City) is a political subdivision of the
State of California. The case arose out of incidents in 2001
and 2002 when respondent Jeff Quon was employed by the
Ontario Police Department (OPD). He was a police ser­
2                     ONTARIO v. QUON

                      Opinion of the Court

geant and member of OPD’s Special Weapons and Tactics
(SWAT) Team. The City, OPD, and OPD’s Chief, Lloyd
Scharf, are petitioners here. As will be discussed, two
respondents share the last name Quon. In this opinion
“Quon” refers to Jeff Quon, for the relevant events mostly
revolve around him.
  In October 2001, the City acquired 20 alphanumeric
pagers capable of sending and receiving text messages.
Arch Wireless Operating Company provided wireless
service for the pagers. Under the City’s service contract
with Arch Wireless, each pager was allotted a limited
number of characters sent or received each month. Usage
in excess of that amount would result in an additional fee.
The City issued pagers to Quon and other SWAT Team
members in order to help the SWAT Team mobilize and
respond to emergency situations.
  Before acquiring the pagers, the City announced a
“Computer Usage, Internet and E-Mail Policy” (Computer
Policy) that applied to all employees. Among other provi­
sions, it specified that the City “reserves the right to moni­
tor and log all network activity including e-mail and
Internet use, with or without notice. Users should have no
expectation of privacy or confidentiality when using these
resources.” App. to Pet. for Cert. 152a. In March 2000,
Quon signed a statement acknowledging that he had read
and understood the Computer Policy.
  The Computer Policy did not apply, on its face, to text
messaging. Text messages share similarities with e-mails,
but the two differ in an important way. In this case, for
instance, an e-mail sent on a City computer was transmit­
ted through the City’s own data servers, but a text mes­
sage sent on one of the City’s pagers was transmitted
using wireless radio frequencies from an individual pager
to a receiving station owned by Arch Wireless. It was
routed through Arch Wireless’ computer network, where it
remained until the recipient’s pager or cellular telephone
                 Cite as: 560 U. S. ____ (2010)           3

                     Opinion of the Court

was ready to receive the message, at which point Arch
Wireless transmitted the message from the transmitting
station nearest to the recipient. After delivery, Arch
Wireless retained a copy on its computer servers. The
message did not pass through computers owned by the
City.
  Although the Computer Policy did not cover text mes­
sages by its explicit terms, the City made clear to employ­
ees, including Quon, that the City would treat text mes­
sages the same way as it treated e-mails. At an April 18,
2002, staff meeting at which Quon was present, Lieuten­
ant Steven Duke, the OPD officer responsible for the City’s
contract with Arch Wireless, told officers that messages
sent on the pagers “are considered e-mail messages. This
means that [text] messages would fall under the City’s
policy as public information and [would be] eligible for
auditing.” App. 30. Duke’s comments were put in writing
in a memorandum sent on April 29, 2002, by Chief Scharf
to Quon and other City personnel.
  Within the first or second billing cycle after the pagers
were distributed, Quon exceeded his monthly text message
character allotment. Duke told Quon about the overage,
and reminded him that messages sent on the pagers were
“considered e-mail and could be audited.” Id., at 40. Duke
said, however, that “it was not his intent to audit [an]
employee’s text messages to see if the overage [was] due to
work related transmissions.” Ibid. Duke suggested that
Quon could reimburse the City for the overage fee rather
than have Duke audit the messages. Quon wrote a check
to the City for the overage. Duke offered the same ar­
rangement to other employees who incurred overage fees.
  Over the next few months, Quon exceeded his character
limit three or four times. Each time he reimbursed the
City. Quon and another officer again incurred overage
fees for their pager usage in August 2002. At a meeting in
October, Duke told Scharf that he had become “ ‘tired of
4                    ONTARIO v. QUON

                     Opinion of the Court

being a bill collector.’ ” Id., at 91. Scharf decided to de­
termine whether the existing character limit was too
low—that is, whether officers such as Quon were having to
pay fees for sending work-related messages—or if the
overages were for personal messages. Scharf told Duke to
request transcripts of text messages sent in August and
September by Quon and the other employee who had
exceeded the character allowance.
  At Duke’s request, an administrative assistant em­
ployed by OPD contacted Arch Wireless. After verifying
that the City was the subscriber on the accounts, Arch
Wireless provided the desired transcripts. Duke reviewed
the transcripts and discovered that many of the messages
sent and received on Quon’s pager were not work related,
and some were sexually explicit. Duke reported his find­
ings to Scharf, who, along with Quon’s immediate supervi­
sor, reviewed the transcripts himself. After his review,
Scharf referred the matter to OPD’s internal affairs divi­
sion for an investigation into whether Quon was violating
OPD rules by pursuing personal matters while on duty.
  The officer in charge of the internal affairs review was
Sergeant Patrick McMahon. Before conducting a review,
McMahon used Quon’s work schedule to redact the tran­
scripts in order to eliminate any messages Quon sent
while off duty. He then reviewed the content of the mes­
sages Quon sent during work hours. McMahon’s report
noted that Quon sent or received 456 messages during
work hours in the month of August 2002, of which no more
than 57 were work related; he sent as many as 80 mes­
sages during a single day at work; and on an average
workday, Quon sent or received 28 messages, of which
only 3 were related to police business. The report con­
cluded that Quon had violated OPD rules. Quon was
allegedly disciplined.
                 Cite as: 560 U. S. ____ (2010)           5

                     Opinion of the Court

                             B
   Raising claims under Rev. Stat. §1979, 42 U. S. C.
§1983; 18 U. S. C. §2701 et seq., popularly known as the
Stored Communications Act (SCA); and California law,
Quon filed suit against petitioners in the United States
District Court for the Central District of California. Arch
Wireless and an individual not relevant here were also
named as defendants. Quon was joined in his suit by
another plaintiff who is not a party before this Court and
by the other respondents, each of whom exchanged text
messages with Quon during August and September 2002:
Jerilyn Quon, Jeff Quon’s then-wife, from whom he was
separated; April Florio, an OPD employee with whom Jeff
Quon was romantically involved; and Steve Trujillo, an­
other member of the OPD SWAT Team. Among the alle­
gations in the complaint was that petitioners violated
respondents’ Fourth Amendment rights and the SCA by
obtaining and reviewing the transcript of Jeff Quon’s
pager messages and that Arch Wireless had violated the
SCA by turning over the transcript to the City.
   The parties filed cross-motions for summary judgment.
The District Court granted Arch Wireless’ motion for
summary judgment on the SCA claim but denied petition­
ers’ motion for summary judgment on the Fourth Amend­
ment claims. Quon v. Arch Wireless Operating Co., 445
F. Supp. 2d 1116 (CD Cal. 2006). Relying on the plural­
ity opinion in O’Connor v. Ortega, 480 U. S. 709, 711
(1987), the District Court determined that Quon had a
reasonable expectation of privacy in the content of his text
messages. Whether the audit of the text messages was
nonetheless reasonable, the District Court concluded,
turned on Chief Scharf’s intent: “[I]f the purpose for the
audit was to determine if Quon was using his pager to
‘play games’ and ‘waste time,’ then the audit was not
constitutionally reasonable”; but if the audit’s purpose
“was to determine the efficacy of the existing character
6                     ONTARIO v. QUON

                      Opinion of the Court

limits to ensure that officers were not paying hidden work­
related costs, . . . no constitutional violation occurred.”
445 F. Supp. 2d, at 1146.
   The District Court held a jury trial to determine the
purpose of the audit. The jury concluded that Scharf
ordered the audit to determine the efficacy of the charac­
ter limits. The District Court accordingly held that peti­
tioners did not violate the Fourth Amendment. It entered
judgment in their favor.
   The United States Court of Appeals for the Ninth Cir­
cuit reversed in part. 529 F. 3d 892 (2008). The panel
agreed with the District Court that Jeff Quon had a rea­
sonable expectation of privacy in his text messages but
disagreed with the District Court about whether the
search was reasonable. Even though the search was
conducted for “a legitimate work-related rationale,” the
Court of Appeals concluded, it “was not reasonable in
scope.” Id., at 908. The panel disagreed with the District
Court’s observation that “there were no less-intrusive
means” that Chief Scharf could have used “to verify the
efficacy of the 25,000 character limit . . . without intruding
on [respondents’] Fourth Amendment rights.” Id., at 908–
909. The opinion pointed to a “host of simple ways” that
the chief could have used instead of the audit, such as
warning Quon at the beginning of the month that his
future messages would be audited, or asking Quon himself
to redact the transcript of his messages. Id., at 909. The
Court of Appeals further concluded that Arch Wireless had
violated the SCA by turning over the transcript to the
City.
   The Ninth Circuit denied a petition for rehearing en
banc. Quon v. Arch Wireless Operating Co., 554 F. 3d 769
(2009). Judge Ikuta, joined by six other Circuit Judges,
dissented. Id., at 774–779. Judge Wardlaw concurred in
the denial of rehearing, defending the panel’s opinion
against the dissent. Id., at 769–774.
                  Cite as: 560 U. S. ____ (2010)            7

                      Opinion of the Court

   This Court granted the petition for certiorari filed by the
City, OPD, and Chief Scharf challenging the Court of
Appeals’ holding that they violated the Fourth Amend­
ment. 558 U. S. ___ (2009). The petition for certiorari
filed by Arch Wireless challenging the Ninth Circuit’s
ruling that Arch Wireless violated the SCA was denied.
USA Mobility Wireless, Inc. v. Quon, 558 U. S. ___ (2009).
                               II
  The Fourth Amendment states: “The right of the people
to be secure in their persons, houses, papers, and effects,
against unreasonable searches and seizures, shall not be
violated . . . .” It is well settled that the Fourth Amend­
ment’s protection extends beyond the sphere of criminal
investigations. Camara v. Municipal Court of City and
County of San Francisco, 387 U. S. 523, 530 (1967). “The
Amendment guarantees the privacy, dignity, and security
of persons against certain arbitrary and invasive acts by
officers of the Government,” without regard to whether the
government actor is investigating crime or performing
another function. Skinner v. Railway Labor Executives’
Assn., 489 U. S. 602, 613–614 (1989). The Fourth Amend­
ment applies as well when the Government acts in its
capacity as an employer. Treasury Employees v. Von
Raab, 489 U. S. 656, 665 (1989).
  The Court discussed this principle in O’Connor. There a
physician employed by a state hospital alleged that hospi­
tal officials investigating workplace misconduct had vio­
lated his Fourth Amendment rights by searching his office
and seizing personal items from his desk and filing cabi­
net. All Members of the Court agreed with the general
principle that “[i]ndividuals do not lose Fourth Amend­
ment rights merely because they work for the government
instead of a private employer.” 480 U. S., at 717 (plurality
opinion); see also id., at 731 (SCALIA, J., concurring in
judgment); id., at 737 (Blackmun, J., dissenting). A major­
8                    ONTARIO v. QUON

                     Opinion of the Court

ity of the Court further agreed that “ ‘special needs, beyond
the normal need for law enforcement,’ ” make the warrant
and probable-cause requirement impracticable for gov­
ernment employers. Id., at 725 (plurality opinion) (quot­
ing New Jersey v. T. L. O., 469 U. S. 325, 351 (1985)
(Blackmun, J., concurring in judgment); 480 U. S., at 732
(opinion of SCALIA, J.) (quoting same).
   The O’Connor Court did disagree on the proper analyti­
cal framework for Fourth Amendment claims against
government employers. A four-Justice plurality concluded
that the correct analysis has two steps. First, because
“some government offices may be so open to fellow em­
ployees or the public that no expectation of privacy is
reasonable,” id., at 718, a court must consider “[t]he opera­
tional realities of the workplace” in order to determine
whether an employee’s Fourth Amendment rights are
implicated, id., at 717. On this view, “the question
whether an employee has a reasonable expectation of
privacy must be addressed on a case-by-case basis.” Id., at
718. Next, where an employee has a legitimate privacy
expectation, an employer’s intrusion on that expectation
“for noninvestigatory, work-related purposes, as well as
for investigations of work-related misconduct, should be
judged by the standard of reasonableness under all the
circumstances.” Id., at 725–726.
   JUSTICE SCALIA, concurring in the judgment, outlined a
different approach. His opinion would have dispensed
with an inquiry into “operational realities” and would
conclude “that the offices of government employees . . . are
covered by Fourth Amendment protections as a general
matter.” Id., at 731. But he would also have held “that
government searches to retrieve work-related materials or
to investigate violations of workplace rules—searches of
the sort that are regarded as reasonable and normal in the
private-employer context—do not violate the Fourth
Amendment.” Id., at 732.
                 Cite as: 560 U. S. ____ (2010)           9

                     Opinion of the Court

   Later, in the Von Raab decision, the Court explained
that “operational realities” could diminish an employee’s
privacy expectations, and that this diminution could be
taken into consideration when assessing the reasonable­
ness of a workplace search. 489 U. S., at 671. In the two
decades since O’Connor, however, the threshold test for
determining the scope of an employee’s Fourth Amend­
ment rights has not been clarified further. Here, though
they disagree on whether Quon had a reasonable expecta­
tion of privacy, both petitioners and respondents start
from the premise that the O’Connor plurality controls.
See Brief for Petitioners 22–28; Brief for Respondents 25–
32. It is not necessary to resolve whether that premise is
correct. The case can be decided by determining that the
search was reasonable even assuming Quon had a reason­
able expectation of privacy.      The two O’Connor ap­
proaches—the plurality’s and JUSTICE SCALIA’s—therefore
lead to the same result here.
                             III 

                              A

  Before turning to the reasonableness of the search, it is
instructive to note the parties’ disagreement over whether
Quon had a reasonable expectation of privacy. The record
does establish that OPD, at the outset, made it clear that
pager messages were not considered private. The City’s
Computer Policy stated that “[u]sers should have no ex­
pectation of privacy or confidentiality when using” City
computers. App. to Pet. for Cert. 152a. Chief Scharf’s
memo and Duke’s statements made clear that this official
policy extended to text messaging. The disagreement, at
least as respondents see the case, is over whether Duke’s
later statements overrode the official policy. Respondents
contend that because Duke told Quon that an audit would
be unnecessary if Quon paid for the overage, Quon rea­
sonably could expect that the contents of his messages
10                   ONTARIO v. QUON

                     Opinion of the Court

would remain private.
   At this point, were we to assume that inquiry into “op­
erational realities” were called for, compare O’Connor, 480
U. S., at 717 (plurality opinion), with id., at 730–731
(opinion of SCALIA, J.); see also id., at 737–738 (Blackmun,
J., dissenting), it would be necessary to ask whether
Duke’s statements could be taken as announcing a change
in OPD policy, and if so, whether he had, in fact or ap­
pearance, the authority to make such a change and to
guarantee the privacy of text messaging. It would also be
necessary to consider whether a review of messages sent
on police pagers, particularly those sent while officers are
on duty, might be justified for other reasons, including
performance evaluations, litigation concerning the lawful­
ness of police actions, and perhaps compliance with state
open records laws. See Brief for Petitioners 35–40 (citing
Cal. Public Records Act, Cal. Govt. Code Ann. §6250 et seq.
(West 2008)). These matters would all bear on the legiti­
macy of an employee’s privacy expectation.
   The Court must proceed with care when considering the
whole concept of privacy expectations in communications
made on electronic equipment owned by a government
employer. The judiciary risks error by elaborating too
fully on the Fourth Amendment implications of emerging
technology before its role in society has become clear. See,
e.g., Olmstead v. United States, 277 U. S. 438 (1928),
overruled by Katz v. United States, 389 U. S. 347, 353
(1967). In Katz, the Court relied on its own knowledge
and experience to conclude that there is a reasonable
expectation of privacy in a telephone booth. See id., at
360–361 (Harlan, J., concurring). It is not so clear that
courts at present are on so sure a ground. Prudence coun­
sels caution before the facts in the instant case are used to
establish far-reaching premises that define the existence,
and extent, of privacy expectations enjoyed by employees
when using employer-provided communication devices.
                 Cite as: 560 U. S. ____ (2010)          11

                     Opinion of the Court

   Rapid changes in the dynamics of communication and
information transmission are evident not just in the tech­
nology itself but in what society accepts as proper behav­
ior. As one amici brief notes, many employers expect or at
least tolerate personal use of such equipment by employ­
ees because it often increases worker efficiency. See Brief
for Electronic Frontier Foundation et al. 16–20. Another
amicus points out that the law is beginning to respond to
these developments, as some States have recently passed
statutes requiring employers to notify employees when
monitoring their electronic communications. See Brief for
New York Intellectual Property Law Association 22 (citing
Del. Code Ann., Tit. 19, §705 (2005); Conn. Gen. Stat. Ann.
§31–48d (West 2003)). At present, it is uncertain how
workplace norms, and the law’s treatment of them, will
evolve.
   Even if the Court were certain that the O’Connor plural­
ity’s approach were the right one, the Court would have
difficulty predicting how employees’ privacy expectations
will be shaped by those changes or the degree to which
society will be prepared to recognize those expectations as
reasonable. See 480 U. S., at 715. Cell phone and text
message communications are so pervasive that some
persons may consider them to be essential means or nec­
essary instruments for self-expression, even self­
identification. That might strengthen the case for an
expectation of privacy. On the other hand, the ubiquity of
those devices has made them generally affordable, so one
could counter that employees who need cell phones or
similar devices for personal matters can purchase and pay
for their own. And employer policies concerning commu­
nications will of course shape the reasonable expectations
of their employees, especially to the extent that such
policies are clearly communicated.
   A broad holding concerning employees’ privacy expecta­
tions vis-à-vis employer-provided technological equipment
12                   ONTARIO v. QUON

                     Opinion of the Court

might have implications for future cases that cannot be
predicted. It is preferable to dispose of this case on nar­
rower grounds. For present purposes we assume several
propositions arguendo: First, Quon had a reasonable
expectation of privacy in the text messages sent on the
pager provided to him by the City; second, petitioners’
review of the transcript constituted a search within the
meaning of the Fourth Amendment; and third, the princi­
ples applicable to a government employer’s search of an
employee’s physical office apply with at least the same
force when the employer intrudes on the employee’s pri­
vacy in the electronic sphere.
                               B
   Even if Quon had a reasonable expectation of privacy in
his text messages, petitioners did not necessarily violate
the Fourth Amendment by obtaining and reviewing the
transcripts. Although as a general matter, warrantless
searches “are per se unreasonable under the Fourth
Amendment,” there are “a few specifically established and
well-delineated exceptions” to that general rule. Katz,
supra, at 357. The Court has held that the “ ‘special
needs’ ” of the workplace justify one such exception.
O’Connor, 480 U. S., at 725 (plurality opinion); id., at 732
(SCALIA, J., concurring in judgment); Von Raab, 489 U. S.,
at 666–667.
   Under the approach of the O’Connor plurality, when
conducted for a “noninvestigatory, work-related purpos[e]”
or for the “investigatio[n] of work-related misconduct,” a
government employer’s warrantless search is reasonable if
it is “ ‘justified at its inception’ ” and if “ ‘the measures
adopted are reasonably related to the objectives of the
search and not excessively intrusive in light of’ ” the cir­
cumstances giving rise to the search. 480 U. S., at 725–
726. The search here satisfied the standard of the
O’Connor plurality and was reasonable under that ap­
                 Cite as: 560 U. S. ____ (2010)           13

                     Opinion of the Court

proach.
  The search was justified at its inception because there
were “reasonable grounds for suspecting that the search
[was] necessary for a noninvestigatory work-related pur­
pose.” Id., at 726. As a jury found, Chief Scharf ordered
the search in order to determine whether the character
limit on the City’s contract with Arch Wireless was suffi­
cient to meet the City’s needs. This was, as the Ninth
Circuit noted, a “legitimate work-related rationale.” 529
F. 3d, at 908. The City and OPD had a legitimate interest
in ensuring that employees were not being forced to pay
out of their own pockets for work-related expenses, or on
the other hand that the City was not paying for extensive
personal communications.
  As for the scope of the search, reviewing the transcripts
was reasonable because it was an efficient and expedient
way to determine whether Quon’s overages were the result
of work-related messaging or personal use. The review
was also not “ ‘excessively intrusive.’ ” O’Connor, supra, at
726 (plurality opinion). Although Quon had gone over his
monthly allotment a number of times, OPD requested
transcripts for only the months of August and September
2002. While it may have been reasonable as well for OPD
to review transcripts of all the months in which Quon
exceeded his allowance, it was certainly reasonable for
OPD to review messages for just two months in order to
obtain a large enough sample to decide whether the char­
acter limits were efficacious. And it is worth noting that
during his internal affairs investigation, McMahon re­
dacted all messages Quon sent while off duty, a measure
which reduced the intrusiveness of any further review of
the transcripts.
  Furthermore, and again on the assumption that Quon
had a reasonable expectation of privacy in the contents of
his messages, the extent of an expectation is relevant to
assessing whether the search was too intrusive. See Von
14                    ONTARIO v. QUON

                      Opinion of the Court

Raab, supra, at 671; cf. Vernonia School Dist. 47J v. Ac
ton, 515 U. S. 646, 654–657 (1995). Even if he could as­
sume some level of privacy would inhere in his messages,
it would not have been reasonable for Quon to conclude
that his messages were in all circumstances immune from
scrutiny. Quon was told that his messages were subject to
auditing. As a law enforcement officer, he would or should
have known that his actions were likely to come under
legal scrutiny, and that this might entail an analysis of his
on-the-job communications. Under the circumstances, a
reasonable employee would be aware that sound manage­
ment principles might require the audit of messages to
determine whether the pager was being appropriately
used. Given that the City issued the pagers to Quon and
other SWAT Team members in order to help them more
quickly respond to crises—and given that Quon had re­
ceived no assurances of privacy—Quon could have antici­
pated that it might be necessary for the City to audit
pager messages to assess the SWAT Team’s performance
in particular emergency situations.
   From OPD’s perspective, the fact that Quon likely had
only a limited privacy expectation, with boundaries that
we need not here explore, lessened the risk that the review
would intrude on highly private details of Quon’s life.
OPD’s audit of messages on Quon’s employer-provided
pager was not nearly as intrusive as a search of his per­
sonal e-mail account or pager, or a wiretap on his home
phone line, would have been. That the search did reveal
intimate details of Quon’s life does not make it unreason­
able, for under the circumstances a reasonable employer
would not expect that such a review would intrude on such
matters. The search was permissible in its scope.
   The Court of Appeals erred in finding the search unrea­
sonable. It pointed to a “host of simple ways to verify the
efficacy of the 25,000 character limit . . . without intruding
on [respondents’] Fourth Amendment rights.” 529 F. 3d,
                 Cite as: 560 U. S. ____ (2010)           15

                     Opinion of the Court

at 909. The panel suggested that Scharf “could have
warned Quon that for the month of September he was
forbidden from using his pager for personal communica­
tions, and that the contents of all his messages would be
reviewed to ensure the pager was used only for work­
related purposes during that time frame. Alternatively, if
[OPD] wanted to review past usage, it could have asked
Quon to count the characters himself, or asked him to
redact personal messages and grant permission to [OPD]
to review the redacted transcript.” Ibid.
   This approach was inconsistent with controlling prece­
dents. This Court has “repeatedly refused to declare that
only the ‘least intrusive’ search practicable can be reason­
able under the Fourth Amendment.” Vernonia, supra, at
663; see also, e.g., Board of Ed. of Independent School Dist.
No. 92 of Pottawatomie Cty. v. Earls, 536 U. S. 822, 837
(2002); Illinois v. Lafayette, 462 U. S. 640, 647 (1983).
That rationale “could raise insuperable barriers to the
exercise of virtually all search-and-seizure powers,”
United States v. Martinez-Fuerte, 428 U. S. 543, 557, n. 12
(1976), because “judges engaged in post hoc evaluations of
government conduct can almost always imagine some
alternative means by which the objectives of the govern­
ment might have been accomplished,” Skinner, 489 U. S.,
at 629, n. 9 (internal quotation marks and brackets omit­
ted). The analytic errors of the Court of Appeals in this
case illustrate the necessity of this principle. Even assum­
ing there were ways that OPD could have performed the
search that would have been less intrusive, it does not
follow that the search as conducted was unreasonable.
   Respondents argue that the search was per se unrea­
sonable in light of the Court of Appeals’ conclusion that
Arch Wireless violated the SCA by giving the City the
transcripts of Quon’s text messages. The merits of the
SCA claim are not before us. But even if the Court of
Appeals was correct to conclude that the SCA forbade
16                   ONTARIO v. QUON

                     Opinion of the Court

Arch Wireless from turning over the transcripts, it does
not follow that petitioners’ actions were unreasonable.
Respondents point to no authority for the proposition that
the existence of statutory protection renders a search per
se unreasonable under the Fourth Amendment. And the
precedents counsel otherwise. See Virginia v. Moore, 553
U. S. 164, 168 (2008) (search incident to an arrest that
was illegal under state law was reasonable); California v.
Greenwood, 486 U. S. 35, 43 (1988) (rejecting argument
that if state law forbade police search of individual’s gar­
bage the search would violate the Fourth Amendment).
Furthermore, respondents do not maintain that any OPD
employee either violated the law him- or herself or knew
or should have known that Arch Wireless, by turning over
the transcript, would have violated the law. The other­
wise reasonable search by OPD is not rendered unreason­
able by the assumption that Arch Wireless violated the
SCA by turning over the transcripts.
  Because the search was motivated by a legitimate work­
related purpose, and because it was not excessive in scope,
the search was reasonable under the approach of the
O’Connor plurality. 480 U. S., at 726. For these same
reasons—that the employer had a legitimate reason for
the search, and that the search was not excessively intru­
sive in light of that justification—the Court also concludes
that the search would be “regarded as reasonable and
normal in the private-employer context” and would satisfy
the approach of JUSTICE SCALIA’s concurrence. Id., at 732.
The search was reasonable, and the Court of Appeals
erred by holding to the contrary. Petitioners did not vio­
late Quon’s Fourth Amendment rights.
                             C
  Finally, the Court must consider whether the search
violated the Fourth Amendment rights of Jerilyn Quon,
Florio, and Trujillo, the respondents who sent text mes­
                 Cite as: 560 U. S. ____ (2010)          17

                     Opinion of the Court

sages to Jeff Quon. Petitioners and respondents disagree
whether a sender of a text message can have a reasonable
expectation of privacy in a message he knowingly sends to
someone’s employer-provided pager. It is not necessary to
resolve this question in order to dispose of the case, how­
ever. Respondents argue that because “the search was
unreasonable as to Sergeant Quon, it was also unreason­
able as to his correspondents.” Brief for Respondents 60
(some capitalization omitted; boldface deleted). They
make no corollary argument that the search, if reasonable
as to Quon, could nonetheless be unreasonable as to
Quon’s correspondents. See id., at 65–66. In light of this
litigating position and the Court’s conclusion that the
search was reasonable as to Jeff Quon, it necessarily
follows that these other respondents cannot prevail.
                        *    *   *
  Because the search was reasonable, petitioners did not
violate respondents’ Fourth Amendment rights, and the
court below erred by concluding otherwise. The judgment
of the Court of Appeals for the Ninth Circuit is reversed,
and the case is remanded for further proceedings consis­
tent with this opinion.
                                          It is so ordered.
                  Cite as: 560 U. S. ____ (2010)            1

                     STEVENS, J., concurring

SUPREME COURT OF THE UNITED STATES
                          _________________

                          No. 08–1332
                          _________________


       CITY OF ONTARIO, CALIFORNIA, ET AL., 

         PETITIONERS v. JEFF QUON ET AL. 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE NINTH CIRCUIT

                         [June 17, 2010] 


   JUSTICE STEVENS, concurring.
   Although I join the Court’s opinion in full, I write sepa
rately to highlight that the Court has sensibly declined to
resolve whether the plurality opinion in O’Connor v. Or
tega, 480 U. S. 709 (1987), provides the correct approach to
determining an employee’s reasonable expectation of
privacy. See ante, at 9. Justice Blackmun, writing for the
four dissenting Justices in O’Connor, agreed with JUSTICE
SCALIA that an employee enjoys a reasonable expectation
of privacy in his office. 480 U. S., at 737. But he advo
cated a third approach to the reasonable expectation of
privacy inquiry, separate from those proposed by the
O’Connor plurality and by JUSTICE SCALIA, see ante, at 8.
Recognizing that it is particularly important to safeguard
“a public employee’s expectation of privacy in the work
place” in light of the “reality of work in modern time,” 480
U. S., at 739, which lacks “tidy distinctions” between
workplace and private activities, ibid., Justice Blackmun
argued that “the precise extent of an employee’s expecta
tion of privacy often turns on the nature of the search,” id.,
at 738. And he emphasized that courts should determine
this expectation in light of the specific facts of each par
ticular search, rather than by announcing a categorical
standard. See id., at 741.
   For the reasons stated at page 13 of the Court’s opinion,
2                         ONTARIO v. QUON

                         STEVENS, J., concurring

it is clear that respondent Jeff Quon, as a law enforcement
officer who served on a SWAT Team, should have under
stood that all of his work-related actions—including all of
his communications on his official pager—were likely to be
subject to public and legal scrutiny. He therefore had only
a limited expectation of privacy in relation to this particu
lar audit of his pager messages. Whether one applies the
reasoning from Justice O’Connor’s opinion, JUSTICE
SCALIA’s concurrence, or Justice Blackmun’s dissent* in
O’Connor, the result is the same: The judgment of the
Court of Appeals in this case must be reversed.




——————
  * I do not contend that Justice Blackmun’s opinion is controlling un
der Marks v. United States, 430 U. S. 188, 193 (1977), but neither is his
approach to evaluating a reasonable expectation of privacy foreclosed
by O’Connor. Indeed, his approach to that inquiry led to the conclusion,
shared by JUSTICE SCALIA but not adopted by the O’Connor plurality,
that an employee had a reasonable expectation of privacy in his office.
See O’Connor v. Ortega, 480 U. S. 709, 718 (1987) (plurality opinion).
But Justice Blackmun would have applied the Fourth Amendment’s
warrant and probable-cause requirements to workplace investigatory
searches, id., at 732 (dissenting opinion), whereas a majority of the
Court rejected that view, see id., at 722, 725 (plurality opinion); id., at
732 (SCALIA, J., concurring in judgment). It was that analysis—
regarding the proper standard for evaluating a search when an em
ployee has a reasonable expectation of privacy—that produced the
opposite result in the case. This case does not implicate that debate
because it does not involve an investigatory search. The jury concluded
that the purpose of the audit was to determine whether the character
limits were sufficient for work-related messages. See ante, at 6.
                     Cite as: 560 U. S. ____ (2010)                   1

                         Opinion of SCALIA, J.

SUPREME COURT OF THE UNITED STATES
                             _________________

                             No. 08–1332
                             _________________


         CITY OF ONTARIO, CALIFORNIA, ET AL., 

           PETITIONERS v. JEFF QUON ET AL. 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE NINTH CIRCUIT

                            [June 17, 2010] 


   JUSTICE SCALIA, concurring in part and concurring in
the judgment.
   I join the Court’s opinion except for Part III–A. I con
tinue to believe that the “operational realities” rubric for
determining the Fourth Amendment’s application to pub
lic employees invented by the plurality in O’Connor v.
Ortega, 480 U. S. 709, 717 (1987), is standardless and
unsupported. Id., at 729–732 (SCALIA, J., concurring in
judgment). In this case, the proper threshold inquiry
should be not whether the Fourth Amendment applies to
messages on public employees’ employer-issued pagers,
but whether it applies in general to such messages on
employer-issued pagers. See id., at 731.
   Here, however, there is no need to answer that thresh
old question. Even accepting at face value Quon’s and his
co-plaintiffs’ claims that the Fourth Amendment applies to
their messages, the city’s search was reasonable, and thus
did not violate the Amendment. See id., at 726 (plurality
opinion); id., at 732 (SCALIA, J., concurring in judgment).
Since it is unnecessary to decide whether the Fourth
Amendment applies, it is unnecessary to resolve which
approach in O’Connor controls: the plurality’s or mine.*
——————
  * Despite his disclaimer, ante, at 2, n. (concurring opinion), JUSTICE
STEVENS’ concurrence implies, ante, at 1–2, that it is also an open
2                         ONTARIO v. QUON

                          Opinion of SCALIA, J.

That should end the matter.
   The Court concedes as much, ante, at 9, 12–17, yet it
inexplicably interrupts its analysis with a recitation of the
parties’ arguments concerning, and an excursus on the
complexity and consequences of answering, that admit
tedly irrelevant threshold question, ante, at 9–12. That
discussion is unnecessary. (To whom do we owe an addi
tional explanation for declining to decide an issue, once we
have explained that it makes no difference?) It also seems
to me exaggerated. Applying the Fourth Amendment to
new technologies may sometimes be difficult, but when it
is necessary to decide a case we have no choice. The
Court’s implication, ante, at 10, that where electronic
privacy is concerned we should decide less than we other
wise would (that is, less than the principle of law neces
sary to resolve the case and guide private action)—or that
we should hedge our bets by concocting case-specific stan
dards or issuing opaque opinions—is in my view indefen
sible. The-times-they-are-a-changin’ is a feeble excuse for
disregard of duty.
   Worse still, the digression is self-defeating. Despite the
Court’s insistence that it is agnostic about the proper test,
lower courts will likely read the Court’s self-described
“instructive” expatiation on how the O’Connor plurality’s
approach would apply here (if it applied), ante, at 9–11, as
a heavy-handed hint about how they should proceed.
Litigants will do likewise, using the threshold question
whether the Fourth Amendment is even implicated as a
——————
question whether the approach advocated by Justice Blackmun in his
dissent in O’Connor is the proper standard. There is room for reason
able debate as to which of the two approaches advocated by Justices
whose votes supported the judgment in O’Connor—the plurality’s and
mine—is controlling under Marks v. United States, 430 U. S. 188, 193
(1977). But unless O’Connor is overruled, it is assuredly false that a
test that would have produced the opposite result in that case is still in
the running.
                 Cite as: 560 U. S. ____ (2010)            3

                     Opinion of SCALIA, J.

basis for bombarding lower courts with arguments about
employer policies, how they were communicated, and
whether they were authorized, as well as the latest trends
in employees’ use of electronic media. In short, in saying
why it is not saying more, the Court says much more than
it should.
   The Court’s inadvertent boosting of the O’Connor plural
ity’s standard is all the more ironic because, in fleshing
out its fears that applying that test to new technologies
will be too hard, the Court underscores the unworkability
of that standard. Any rule that requires evaluating
whether a given gadget is a “necessary instrumen[t] for
self-expression, even self-identification,” on top of assess
ing the degree to which “the law’s treatment of [workplace
norms has] evolve[d],” ante, at 11, is (to put it mildly)
unlikely to yield objective answers.
   I concur in the Court’s judgment.
