                              In the

    United States Court of Appeals
                For the Seventh Circuit
No. 11-2734

UNITED STATES OF AMERICA ,
                                                   Plaintiff-Appellee,

                                 v.


CHARLES TODD STOKES,
                                               Defendant-Appellant.

        Appeal from the United States District Court for the
          Northern District of Illinois, Eastern Division.
         No. 07 CR 590-1— Rebecca R. Pallmeyer, Judge.


     ARGUED MARCH 28, 2012—DECIDED AUGUST 1, 2013



   Before MANION , SYKES, and HAMILTON , Circuit Judges.
    SYKES, Circuit Judge. Charles Todd Stokes was convicted in
Florida state court of misdemeanor battery for indecently
touching two boys at the elementary school where he was a
teacher. A month later, for reasons unknown, Florida authori-
ties permitted him to move to Thailand where he immediately
began enticing adolescent and prepubescent boys for sex. This
went on for several years until someone tipped off the
2                                                    No. 11-2734

U.S. Immigration and Customs Enforcement Service (“ICE”).
In a joint operation with the Royal Thai Police, ICE agents
searched Stokes’s home and recovered a camera, a computer,
and several compact discs containing thousands of images of
Stokes’s sexual activity with Thai boys.
    Stokes was extradited to the United States and convicted of
traveling in foreign commerce for the purpose of engaging in
a sex act with a minor. See 18 U.S.C. § 2423(b). Stokes appeals,
raising no fewer than ten claims of error. None are meritorious.
We concentrate our efforts on two: a procedural mistake in the
extradition process and a challenge to the legality of the search.
    The extradition error involves the Rule of Specialty, which
holds that a nation securing the return of a person pursuant to
an extradition treaty may prosecute the extradited person only
for the crime or crimes named in the surrendering country’s
extradition grant. Thailand surrendered Stokes to face a charge
under 18 U.S.C. § 2423(c), which makes it a crime for
U.S. citizens and lawful permanent residents to engage in illicit
sexual conduct in a foreign place. Prosecutors later shifted
gears and prosecuted him for violating 18 U.S.C. § 2423(b), a
similar crime but not the one on which Thailand granted
extradition. On a request from the American Embassy, how-
ever, the Thai foreign ministry waived the Rule of Specialty.
This diplomatic action cleared the way for the government to
proceed on the substitute charge.
    The challenge to the search raises two questions:
(1) whether an extraterritorial search of an American citizen by
U.S. agents is subject to the Fourth Amendment’s implicit
warrant requirement and the explicit requirements of the
No. 11-2734                                                    3

Warrant Clause; and (2) whether the search by ICE agents was
reasonable. Following the Second Circuit, we hold that the
Fourth Amendment’s warrant requirement and the Warrant
Clause have no extraterritorial application. See In re Terrorist
Bombings of U.S. Embassies in E. Afr., 552 F.3d 157, 171 (2d Cir.
2008). But Stokes remains protected by the Amendment’s
touchstone requirement of reasonableness. See id. at 170 n.7.
Because the search was reasonable, the photographic evidence
was properly admitted at trial.


                          I. Background
   Stokes was a teacher in the Miami-Dade public schools for
more than a decade. On February 25, 2000, he pleaded no
contest to a charge of misdemeanor battery for indecently
touching two boys who were his students. A Florida court
suspended sentence and placed Stokes on probation. As a
condition of his probation, Stokes had to surrender his Florida
teaching license and was barred from unsupervised contact
with minors absent written court permission. Less than a
month after his plea and sentencing, Stokes asked for permis-
sion to complete his probation in Thailand. For reasons not
specified in the record, this request was granted. On March 21,
2000, Stokes moved to Thailand, eventually settling in Pattaya,
about 200 kilometers south of Bangkok.
    Within two weeks of his arrival in Thailand, Stokes began
seeking boys for sex. He frequently hired young male prosti-
tutes. He enticed runaways and other boys off the streets to his
home to play video games, and once there, he engaged in
sexual acts with them. He often photographed these sexual
4                                                  No. 11-2734

encounters, transferring the images from his camera to a
computer and compact discs.
    This conduct continued undetected for several years. With
the exception of a three-week trip to the United States from
December 25, 2001 to January 14, 2002, Stokes resided continu-
ously in Thailand from March 21, 2000, until his arrest on
July 28, 2006. He supported himself by teaching English. In
December 2002 ICE agents based in Thailand received a tip
that Stokes had been fired from a teaching job in Bangkok for
indecently touching male students. The agents opened an
investigation and learned that Stokes had been fired from
another teaching job at a different school based on similar
allegations. This prompted ICE to request assistance from the
Royal Thai Police in Pattaya.
    Thai Police assigned narcotics officers to the investigation
because surveillance was anticipated and the narcotics officers
worked in plain clothes. The Thai officers eventually obtained
a warrant authorizing a search of Stokes’s home “to locate and
seize any illegal items and narcotics … of which possession is
considered illegal, or which was illegally obtained, or which
has been used or is intended to be used to commit a crime.”
Because this was a sex-crimes investigation, the inclusion of
narcotics among the objects of the search was an obvious
anomaly probably attributable to the presence of the local
narcotics officers on the joint law-enforcement team.
   Early in the morning of October 9, 2003, ICE agents and the
Royal Thai Police executed the warrant at Stokes’s home.
Stokes was not there when they arrived, so they waited for him
before entering. Once the search was underway, the officers
No. 11-2734                                                              5

recovered a digital camera, multiple compact discs, and a
computer. Together, these items contained more than
6,000 images of Stokes’s sexual activity with adolescent and
prepubescent Thai boys.
    Despite the voluminous evidence of serious crimes, Stokes
was not arrested until July 28, 2006, almost three years after the
search. It took another year to return him to the United States.
On July 26, 2007, Thailand granted an extradition request from
the United States and returned Stokes to Miami to face a
charge of violating 18 U.S.C. § 2423(c), which makes it a crime
for U.S. citizens and lawful permanent residents to travel in
foreign commerce and engage in illicit sexual conduct. But that
particular subsection of § 2423 was enacted after Stokes
traveled to Thailand and therefore did not apply to his
conduct. Federal prosecutors in Miami soon realized their
mistake and dropped the charge. Stokes was transferred to the
Northern District of Illinois and indicted on three counts of
violating 18 U.S.C. § 2251A(b)(2)(A), a child-trafficking statute.1
Prosecutors dismissed these charges as well and eventually
indicted Stokes on a single count of violating 18 U.S.C.
§ 2423(b), which at the relevant time prohibited traveling in
interstate or foreign commerce for the purpose of engaging in
a sexual act with a person under 18. See 18 U.S.C. § 2423(b)
(effective Oct. 30, 1998 to Nov. 2, 2002).


1
    M ore specifically, 18 U.S.C. § 2251A(b)(2)(A ) provides: “Whoever
purchases or otherwise obtains custody or control of a minor, … with intent
to promote … the engaging in of sexually explicit conduct by such minor
for the purpose of producing any visual depiction of such conduct … shall
be punished by imprisonment for not less than 30 years or for life … .”
6                                                     No. 11-2734

    Stokes moved to suppress the evidence recovered in the
search of his home in Thailand. In a comprehensive opinion,
the district court denied the motion. United States v. Stokes,
710 F. Supp. 2d 689 (N.D. Ill. 2009). The judge first held that the
Fourth Amendment’s warrant requirement and Warrant
Clause do not apply overseas. Id. at 697–70. Next, after consid-
ering all the circumstances, the judge found that the search was
reasonable. Id. at 701–02. Finally, the judge held that even if the
search violated the Fourth Amendment, ICE agents relied in
good faith on Thai legal authorities. Id. at 702–03.
    After a flurry of additional defense motions, all unsuccess-
ful, the case was tried to a jury. The government introduced
testimony from the ICE agents involved in the investigation
and two Thai boys who were sexually assaulted by Stokes. One
of the victims was a street kid nicknamed “Ice,” who was
11 years old when Stokes first enticed him to his home with a
promise of video games and a place to sleep. “Ice” testified that
Stokes subjected him to various sex acts and gave him money.
He recalled approximately 20 such sexual encounters with
Stokes. The other victim was a runaway nicknamed “Note,”
who also was 11 when he first accepted Stokes’s invitation to
accompany him home. “Note” testified to a similar pattern of
sexual abuse by Stokes.
    Finally, the government introduced a representative sample
of the more than 6,000 photographic images recovered during
the search of Stokes’s home. The photographs depicted Stokes
engaged in various sex acts with Thai boys, including “Ice” and
“Note.” An ICE agent testified that approximately 70 different
boys appear in the images, 60 of whom appeared to be under
16. Of those, 30 appeared to be under the age of 12, and the
No. 11-2734                                                        7

youngest looked to be about 7. Several hundred of these
photos were transferred from Stokes’s camera to compact discs
in the months immediately before and after Stokes’s brief trip
to the United States and return to Thailand in December 2001
to January 2002.
   The jury found Stokes guilty. The district judge sentenced
him to 15 years in prison, the maximum penalty. Stokes timely
appealed.


                            II. Discussion
    Stokes has taken a scattershot approach to his appeal,
raising ten separate issues, some of which have subparts. We
take this opportunity to reiterate some advice we’ve given
before: “Losers in a trial can go hunting for relief on appeal
with a rifle or a shotgun. The rifle is better. … [T]he shotgun
approach may hit the target with something but it runs the risk
of obscuring significant issues by dilution.” Gagan v. Am.
Cablevision, Inc., 77 F.3d 951, 955 (7th Cir. 1996) (Evans, J.); see
also Fifth Third Mortg. Co. v. Chi. Title Ins. Co., 692 F.3d 507, 509
(6th Cir. 2012) (“When a party comes to us with nine grounds
for reversing the district court, that usually means there are
none.”). Most of Stokes’s arguments are frivolous or so
obviously meritless that we need only address them sum-
marily. Two require more complete discussion.


A. Rule of Specialty
  Stokes argues that the Rule of Specialty barred the govern-
ment from prosecuting him for violating § 2423(b) because he
8                                                    No. 11-2734

was extradited for a violation of § 2423(c), a different crime.
The Rule of Specialty, a treaty-law doctrine, holds that a nation
seeking return of a person under the terms of an extradition
treaty may prosecute the extradited person only to the extent
expressly authorized by the surrendering nation in the grant of
extradition. See United States v. Warda, 285 F.3d 573, 575–76 (7th
Cir. 2002) (“[T]he Rule of Specialty … does not allow the
country to which an individual is extradited to prosecute that
person for a crime unless the extraditing nation has expressly
authorized such a prosecution.”). Article 14 of the extradition
treaty between the United States and Thailand incorporates the
rule:
           (1) A person extradited under this Treaty
       shall not be detained, tried, or punished in the
       territory of the Requesting State for an offense
       other than that for which extradition has been
       granted … , unless:
           ….
               (c) the Requested State has consented to
           detention, trial, or punishment of that person
           for an offense other than that for which extra-
           dition was granted, or to extradition to a
           third State. …
Extradition Treaty with Thailand, U.S.-Thailand, art. 14,
Dec. 14, 1983, S. TREATY DOC . No. 98–16 (1984), available at 1983
U.S.T. LEXIS 418 (entered into force May 17, 1991) (emphasis
added). As we will see, the “unless” clause is important here.
No. 11-2734                                                    9

    Stokes was extradited on a charge of engaging in illicit
sexual conduct in a foreign place in violation of 18 U.S.C.
§ 2423(c). Adopted as part of the 2003 PROTECT Act, this
statute provides that “[a]ny United States citizen … who
travels in foreign commerce, and engages in any illicit sexual
conduct with another person shall be … imprisoned not more
than 30 years.“ See Prosecutorial Remedies and Tools Against
the Exploitation of Children Today Act of 2003 (“PROTECT
Act”), Pub. L. No. 108–21, 117 Stat. 650 (amending 18 U.S.C.
§ 2423 and adding subsection (c)). However, because Stokes’s
last travel to Thailand occurred in January 2002, § 2423(c) could
not be applied to his conduct. See United States v. Jackson,
480 F.3d 1014, 1018, 1024 (9th Cir. 2007) (holding that § 2423(c)
does not apply to travel occurring prior to the enactment of the
statute and thus finding no need to consider ex post facto
argument).
   Prosecutors in Miami quickly realized the mistake and
moved to dismiss the § 2423(c) charge. Stokes was then
transferred to the Northern District of Illinois, and the
government indicted him on three counts of violating
§ 2251A(b), which prohibits child trafficking. This, too, was a
charging misfire, and the charges were dismissed. The govern-
ment eventually obtained an indictment charging Stokes with
a single violation of § 2423(b), which at the relevant time
prohibited traveling in interstate or foreign commerce for the
purpose of engaging in a sexual act with a person under the
age of 18.
   Stokes insists that the Rule of Specialty barred the govern-
ment from prosecuting him on the substitute charge. The
government responds that Stokes lacks standing to assert a
10                                                   No. 11-2734

violation of the Rule of Specialty, relying on authority from
this court holding that extradition treaties govern diplomatic
relations only and do not create enforceable personal rights.
See United States v. Burke, 425 F.3d 400, 408 (7th Cir. 2005)
(“[E]xtradition treaties do not create personal rights enforce-
able by criminal defendants. … Instead they create rules for the
relations between nations.” (citing Matta-Ballesteros v. Henman,
896 F.2d 255, 259 (7th Cir. 1990))).
    On the face of it, Burke appears to foreclose further inquiry
into the Rule of Specialty. But there is reason to question this
circuit precedent. In United States v. Rauscher, 119 U.S. 407
(1886), the Supreme Court recognized and enforced the Rule of
Specialty in a prosecution of an American seaman captured by
Great Britain on the high seas and surrendered to the United
States to face a charge of murder under the terms of the
extradition treaty between the two countries. After extradition
the government tried and convicted the seaman on a different
charge: infliction of cruel and unusual punishment. The
Supreme Court enforced the doctrine of specialty derived from
treaty law, explaining that
       [a] treaty … is a law of the land, as an act of
       congress is, whenever its provisions prescribe a
       rule by which the rights of the private citizen or
       subject may be determined. And, when such
       rights are of a nature to be enforced in a court of
       justice, that court resorts to the treaty for a rule
       of decision for the case before it as it would to a
       statute.
No. 11-2734                                                      11

Id. at 419. Under the extradition treaty then in effect between
the United States and Great Britain, murder was an extradit-
able offense but the substitute crime, infliction of cruel and
unusual punishment, was not. Applying the Rule of Specialty,
the Court held that a person brought within the jurisdiction of
the court under an extradition treaty
       can only be tried for one of the offenses de-
       scribed in that treaty, and for the offense with
       which he is charged in the proceedings for his
       extradition, until a reasonable time and opportu-
       nity have been given him, after his release or trial
       upon such charge, to return to the country from
       whose asylum he had been forcibly taken under
       those proceedings.
Id. at 430.
    Our decision in Burke is hard to square with Rauscher, which
though old remains good law today. See United States v.
Alvarez-Machain, 504 U.S. 655, 659 (1992) (recognizing the
continued applicability of Rauscher, but distinguishing it where
the presence of the defendant was secured by forcible abduc-
tion rather than extradition). Indeed, we have specifically
acknowledged Rauscher’s holding in another case, though not
one raising an extradition question. See Jogi v. Voges, 480 F.3d
822, 831 (7th Cir. 2007) (citing Rauscher as holding that the Rule
of Specialty in an extradition treaty may be asserted as a
defense to a prosecution for a crime other than the one on
which extradition was based). Several of our sister circuits have
specifically held that criminal defendants have standing to
raise a violation of the Rule of Specialty. See, e.g., United States
12                                                    No. 11-2734

v. Puentes, 50 F.3d 1567, 1574 (11th Cir. 1995) (“We believe that
Rauscher clearly confers such a right on the extradited defen-
dant.”); United States v. Levy, 905 F.2d 326, 328 n.1 (10th Cir.
1990) (“Levy has standing to raise the issue.”); United States v.
Cuevas, 847 F.2d 1417, 1426 (9th Cir. 1988) (“A person extra-
dited may raise whatever objections the extraditing country
would have been entitled to raise.”); United States v. Thirion,
813 F.2d 146, 151 (8th Cir. 1987) (“[The defendant] may raise
whatever objections to his prosecution that Monaco might
have.” (citing Rauscher, 119 U.S. at 419)).
    Although we question whether Burke can be reconciled
with Rauscher, Jogi, and the authority from other circuits, we do
not need to resolve the matter here. It is well-established that
the Rule of Specialty may be waived by the surrendering
country. See United States v. Tse, 135 F.3d 200, 205 (1st Cir. 1998)
(“If Hong Kong consented to the prosecution[,] … Tse’s posi-
tion must fail.”); Puentes, 50 F.3d at 1575 (“As a sovereign, the
requested nation may waive its right to object to a treaty
violation and thereby deny the defendant standing to object to
such an action.”); Thirion, 813 F.2d at 151 (“While the asylum
country may consent to extradite the defendant for offenses
other than those expressly enumerated in the treaty, … it did
not do so here.”); United States v. Najohn, 785 F.2d 1420, 1422
(9th Cir. 1986) (“[T]he protection [of specialty] exists only to the
extent that the surrendering country wishes.”). As we have
noted, the extradition treaty between the United States and
Thailand expressly provides for waivers of the Rule of
Specialty, and diplomatic authorities in the two nations
invoked that waiver procedure here.
No. 11-2734                                                   13

    On December 8, 2008, the Thai Ministry of Foreign Affairs
issued a communiqué to the United States Embassy expressly
stating that Thailand
       consents to the waiver of the rule of speciality,
       viz., to the detention, trial, and punishment of
       Mr. Charles Todd Stokes for an offence under
       Title 18 of the United States Code,
       Section 2423(b) which is technically different
       from Title 18 of the United States Code,
       Section 2423(c) for which the extradition was
       granted.
    Stokes argues that we cannot rely on Thailand’s waiver
absent further inquiry into how it was obtained. To the
contrary, Thailand’s waiver of the Rule of Specialty is conclu-
sive on the question. Tse, 135 F.3d at 205; Puentes, 50 F.3d at
1575 (“The extradited individual … enjoys [the Rule of Spe-
cialty] right at the sufferance of the requested nation. As a
sovereign, the requested nation may waive its right to object to
a treaty violation … .“). Further inquiry is unnecessary.


B. The Search of Stokes’s Home in Thailand
    Stokes also challenges the district court’s decision denying
his motion to suppress the photographic evidence recovered in
the search of his home in Pattaya. The photographs led to the
identification of the two Thai victims who testified against him,
and the government introduced a representative sample of the
photographs at trial. In denying suppression the district judge
concluded that the Fourth Amendment generally applied but
14                                                    No. 11-2734

the Amendment’s warrant requirement and Warrant Clause
did not. The judge also found the search reasonable under all
the circumstances. Alternatively, the judge held that even if the
search violated the Fourth Amendment, the exclusionary rule
would not apply because the ICE agents relied in good faith on
Thai law-enforcement authorities. We review the district
court’s decision under a split standard of review; factual
findings are reviewed for clear error, and legal conclusions and
the ultimate determination of reasonableness are subject to de
novo review. United States v. Uribe, 709 F.3d 646, 649 (7th Cir.
2013).


     1. Extraterritorial Application of the Fourth Amendment
    Evidence obtained in a search of an American citizen by
foreign authorities operating within their own country is
generally admissible in the courts of the United States even if
the search does not otherwise comply with our law, including
the law of the Fourth Amendment. See United States v. Emman-
uel, 565 F.3d 1324, 1330 (11th Cir. 2009) (“The general rule is
that evidence obtained from searches carried out by foreign
officials in their own countries is admissible in United States
courts, even if the search would not otherwise comply with
United States law or the law of the foreign country.”); United
States v. Barona, 56 F.3d 1087, 1096 (9th Cir. 1995); United States
v. Peterson, 812 F.2d 486, 490 (9th Cir. 1987); United States v.
Morrow, 537 F.2d 120, 140 (5th Cir. 1976). But if U.S. agents
substantially participate in an extraterritorial search of a
U.S. citizen and the foreign officials were essentially acting as
agents for their American counterparts or the search amounted
No. 11-2734                                                   15

to a joint operation between American and foreign authorities,
the Fourth Amendment generally applies. See Emmanuel,
565 F.3d at 1330; Barona, 56 F.3d at 1096; Peterson, 812 F.2d at
490; cf. United States v. Marzano, 537 F.2d 257, 269–71 (7th Cir.
1976) (holding that FBI agents who merely supplied informa-
tion to Grand Cayman police and observed but did not
participate in the search by authorities in that country did not
trigger Fourth Amendment protection).
    The district court held that because the ICE agents initiated
the investigation of Stokes and fully participated in the search
of his home, the search was a joint operation between Ameri-
can and Thai authorities and “some measure” of Fourth
Amendment protection applied. Stokes, 710 F. Supp. 2d at 697.
The government does not contest this ruling, for good reason.
On these facts we agree with the district court that the Fourth
Amendment generally applies.
   That conclusion, however, does not answer the more
precise question about the extraterritorial reach of the Amend-
ment’s warrant requirements. The Fourth Amendment
provides:
       The right of the people to be secure in their
       persons, houses, papers, and effects, against
       unreasonable searches and seizures, shall not be
       violated, and no Warrants shall issue, but upon
       probable cause, supported by Oath or affirma-
       tion, and particularly describing the place to be
       searched, and the persons or things to be seized.
U.S. CONST. amend. IV. Stokes argues that the Thai warrant
violated the Warrant Clause because it did not describe the
16                                                                     No. 11-2734

items to be seized with particularity and the search exceeded
the scope of the warrant. There is no question that the warrant
used very general language. Stokes’s argument thus requires
us to decide whether an extraterritorial search by U.S. agents
is subject to the Warrant Clause.
    The Warrant Clause is phrased as a limitation on the power
to issue warrants and is distinct from the Fourth Amendment’s
“warrant requirement,” which though not expressed in the text
of the Amendment is implied as a matter of long-standing
Supreme Court doctrine.2 See Kentucky v. King, 131 S. Ct. 1849,
1856 (2011) (“Although the text of the Fourth Amendment does
not specify when a search warrant must be obtained, this Court
has inferred that a warrant must generally be secured.”);
Brigham City v. Stuart, 547 U.S. 398, 403 (2006) (“searches and
seizures inside a home without a warrant are presumptively
unreasonable”); Payton v. New York, 445 U.S. 573, 586–87 (1980).
The Supreme Court has never addressed whether the Warrant
Clause or the doctrinal requirement of a warrant applies
extraterritorially. Nor have we.

2
  Because warrants immunized government agents against liability for tres-
pass, the Fourth Amendment’s W arrant Clause aimed to limit their
availability by imposing explicit requirements on their issuance. See A K H IL
R EED A M A R , T H E B ILL O F R IGH TS : C REA TIO N A N D R EC O N STRU C TIO N 68–76
(1998); Akhil Reed Amar, Fourth Amendment First Principles, 107 H A RV . L.
R EV . 757, 761–81 (1994); W illiam J. Stuntz, The Substantive Origins of Criminal
Procedure, 105 Y ALE L.J. 393, 409–10 (1995). The “warrant requirement” in
modern Fourth Amendment doctrine arises by implication and operates as
a general presumption that warrantless searches are unreasonable, subject
to certain well-established exceptions. See Kentucky v. King, 131 S. Ct. 1849,
1856 (2011); Brigham City v. Stuart, 547 U.S. 398, 403 (2006); Groh v. Ramirez,
540 U.S. 551, 559 (2004); Payton v. New York, 445 U.S. 573, 586–87 (1980).
No. 11-2734                                                   17

    The Supreme Court’s reasoning in United States v. Verdugo-
Urquidez, 494 U.S. 259 (1990), sheds some light on the question.
In Verdugo-Urquidez the Court held that the Fourth Amend-
ment has no application to a warrantless search by U.S. agents
of a nonresident alien’s property located in a foreign coun-
try—there, Mexico. Id. at 261. The Court based its holding on
“the text of the Fourth Amendment, its history, and [the
Court’s] cases discussing the application of the Constitution to
aliens and extraterritorially.” Id. at 274. Because the Amend-
ment did not apply at all, the Court had no need to separately
address whether the warrant requirement and the Warrant
Clause applied to foreign searches by American agents. But the
Court noted in passing that any warrant issued by a judicial
officer in this country “would be a dead letter outside the
United States.” Id. Justice Kennedy’s concurring opinion was
more direct:
       The absence of local judges or magistrates avail-
       able to issue warrants, the differing and perhaps
       unascertainable conceptions of reasonableness
       and privacy that prevail abroad, and the need to
       cooperate with foreign officials all indicate that
       the Fourth Amendment’s warrant requirement
       should not apply in Mexico as it does in this
       country.
Id. at 278 (Kennedy, J., concurring). Justice Stevens echoed the
point in his concurrence, as did Justice Blackmun in dissent. See
id. at 279 (Stevens, J., concurring in the judgment) (“I do not
believe the Warrant Clause has any application to searches of
noncitizens’ homes in foreign jurisdictions because American
18                                                 No. 11-2734

magistrates have no power to authorize such searches.”); id. at
297 (Blackmun, J., dissenting) (“[A]n American magistrate’s
lack of power to authorize a search abroad renders the Warrant
Clause inapplicable to the search of a noncitizen’s residence
outside this country.”).
    Among the circuit courts of appeals, only the Second has
addressed whether the Fourth Amendment’s warrant require-
ment applies to searches conducted by U.S. agents overseas,
concluding that it does not. See In re Terrorist Bombings,
552 F.3d at 167 (“[W]e hold that the Fourth Amendment’s
warrant requirement does not govern searches conducted
abroad by U.S. agents; such searches of U.S. citizens need only
satisfy the Fourth Amendment’s requirement of reasonable-
ness.”). The Second Circuit took its cues from Verdugo-
Urquidez, in which no fewer than “seven justices of the
Supreme Court endorsed the view that U.S. courts are not
empowered to issue warrants for foreign searches.” Id. at 169.
    Beyond reading the clear signals from the Supreme Court
in Verdugo-Urquidez, the Second Circuit noted the absence of
any historical support for the argument that the Fourth Amend-
ment’s warrant requirement applies to searches carried out by
U.S. agents overseas. Id. (“[T]here is nothing in our history or
our precedents suggesting that U.S. officials must first obtain
a warrant before conducting an overseas search.”). The court
also considered the foreign-policy implications of extending
the warrant requirement to extraterritorial searches, noting
that “nothing in the history of the foreign relations of the
United States would require that U.S. officials obtain warrants
from foreign magistrates … or, indeed, to suppose that all
No. 11-2734                                                       19

other states have search and investigation rules akin to our
own.” Id. at 170.
    Finally, the court returned to the basic difficulty that “if
U.S. judicial officers were to issue search warrants intended to
have extraterritorial effect, such warrants would have dubious
legal significance, if any, in a foreign nation.” Id. at 171. And “it
is by no means clear that U.S. judicial officers could be autho-
rized to issue warrants for overseas searches.” Id. For these
reasons, the court concluded that “the Fourth Amendment’s
Warrant Clause has no extraterritorial application,” and
“foreign searches of U.S. citizens conducted by U.S. agents are
subject only to the Fourth Amendment’s requirement of
reasonableness.” Id.
    Stokes has no response to In re Terrorist Bombings. Nor does
he grapple with the clear implication of the Supreme Court’s
statements in Verdugo-Urquidez. We agree with the Second
Circuit’s reasoning and now hold that the Fourth Amend-
ment’s warrant requirement, and by extension the strictures of
the Warrant Clause, do not apply to extraterritorial searches by
U.S. agents. The search of Stokes’s home in Thailand is
governed by the Amendment’s basic requirement of reason-
ableness, see In re Terrorist Bombings, 552 F.3d at 170 n.7, to
which we now turn.


   2. Reasonableness of the Search
   Whether a search is reasonable under the Fourth Amend-
ment depends on the totality of the circumstances and requires
the court to weigh the intrusion on individual privacy against
20                                                   No. 11-2734

the government’s need for information and evidence. Samson
v. California, 547 U.S. 843, 848 (2006). On the individual side of
the ledger, the privacy of the home is central to the Fourth
Amendment right. See Kyllo v. United States, 533 U.S. 27, 31
(2001). Against that core individual right is the government’s
strong interest in preventing the sexual exploitation of chil-
dren.
    In finding the search reasonable, the district court was
heavily influenced by the fact that the joint investigation by
ICE and the Royal Thai Police had produced information that
“almost certainly” would have been sufficient to establish
probable cause that Stokes had committed a crime and evi-
dence of it would be found in his home. Stokes, 710 F. Supp. 2d
at 701. We agree but omit the qualifier “almost.” Probable
cause requires a commonsense “assessment of probabilities in
particular factual contexts,” Illinois v. Gates, 462 U.S. 213, 232
(1983), and here the district court marshaled the compelling
evidence supporting probable cause:
       Stokes had been fired from two Thai schools in
       one year for touching children inappropriately.
       His colleagues at a third school told investigators
       that he continued to engage in similar behavior.
       Stokes had a history of sexually assaulting
       children[] and a criminal conviction for inappro-
       priately touching a child in the United States. He
       was seen regularly hugging and kissing one
       particular male student. Two credible informants
       separately indicated that Stokes, an unmarried,
       middle-aged man, intimated that he was sexually
       attracted to children and boasted about living
No. 11-2734                                                  21

       with young Thai boys. ICE Investigators also
       verified through cooperation with Thai authori-
       ties that a witness had, on at least one occasion,
       seen young boys reporting to Stokes’s private
       quarters.
Stokes, 710 F. Supp. 2d at 701.
    Moreover, the search was executed in a reasonable manner.
The law-enforcement team acted pursuant to a valid Thai
search warrant. The search took place during the daytime
hours. Although Stokes was not at home when the officers
arrived early in the morning, they waited for him before
entering the home. Stokes was not restrained during the
search, containers were not broken open, and Stokes received
an inventory of the items seized. The entire search lasted only
about two hours. In the district court’s view, “Thai and
U.S. officials acted reasonably to minimize the intrusiveness of
the search.” Id. at 702. Again, we agree. Because the search of
Stokes’s home was reasonable, the district court properly
denied suppression of the evidence recovered there.


C. Remaining Claims
   Stokes raises a bevy of additional arguments, some down-
right frivolous and the rest simply meritless. We move through
the remaining issues with more dispatch.
22                                                         No. 11-2734

     1. Commerce Clause Challenge to 18 U.S.C. § 2423(b)
    Relying on United States v. Lopez, 514 U.S. 549 (1995), and
United States v. Morrison, 529 U.S. 598 (2000), Stokes argues that
§ 2423(b) exceeds Congress’s power under the Commerce
Clause.3 Neither Lopez nor Morrison is helpful here. In Lopez the
Supreme Court explained that Congress is authorized under
the Commerce Clause to regulate three categories of activity:
(1) the use of the channels of interstate commerce; (2) the use
of the instrumentalities of interstate commerce, or persons or
things in interstate commerce; and (3) activities that have a
substantial relation to interstate commerce (that is, that
substantially affect interstate commerce). See Lopez, 514 U.S. at
558–59. Lopez and Morrison raised questions about the limits of
the third category—the “substantial effects” power—but
§ 2423(b) fits comfortably within the first category, the
“channels power.” The statute makes it a crime to travel in
interstate or foreign commerce “for the purpose of engaging in
any sexual act … with a person under 18 years of age.”
18 U.S.C. § 2423(b) (effective Oct. 30, 1998 to Nov. 1, 2002).
    In keeping with these general principles, several circuits
have held that § 2423(b) is a proper exercise of the channels
power. See, e.g., United States v. Tykarsky, 446 F.3d 458, 470 (3d
Cir. 2006); United States v. Han, 230 F.3d 560, 562–63 (2d Cir.
2000). It’s worth emphasizing here that Stokes’s case does not
implicate the usual federalism concerns that animate most
Commerce Clause challenges. “Foreign commerce is

3
  The Commerce Clause provides: “The Congress shall have Power … To
regulate Commerce with foreign Nations, and among the several States, and
with Indian Tribes … .” U.S. C O N ST . art. 1, § 8, cl. 3.
No. 11-2734                                                      23

pre-eminently a matter of national concern.” Japan Line, Ltd. v.
County of Los Angeles, 441 U.S. 434, 448 (1979). In this regard,
the Fifth Circuit has affirmed a conviction under § 2423(b) on
almost identical facts. See United States v. Bredimus, 352 F.3d
200, 208 (5th Cir. 2003). In Bredimus the defendant was con-
victed of traveling to Thailand for the purpose of engaging in
sexual acts with minors. Id. at 201. The court rejected the
defendant’s Commerce Clause challenge to § 2423(b). Id. at
204–08.
    Relatedly, Stokes contends that § 2423(b) is unconstitutional
because it criminalizes “mere thought” in interstate or foreign
commerce. Not so. The statute targets the use of the channels
of interstate and foreign commerce for a particular illicit
purpose—the purpose of engaging in a sexual act with a
minor—and not just “mere thought” in interstate or foreign
commerce. As the First Circuit noted in rejecting a similar
argument, “[p]roof of intent naturally means proving state of
mind, but that does not mean that one is punishing ‘mere
thought’ any more than that the requirement of proving mens
rea in most crimes means that one is solely punishing ‘mere
thought.’ ” United States v. Gamache, 156 F.3d 1, 8 (1st Cir. 1998).
Section 2423(b) lies well within Congress’s power under the
Commerce Clause.


   2. Vagueness Challenge to 18 U.S.C. § 2423(b)
    Stokes also contends that § 2423(b) is unconstitutionally
vague. This argument requires an examination of the full text
of § 2423(b) as it stood at the time of Stokes’s travel:
24                                                    No. 11-2734

       A person who travels in interstate commerce, or
       conspires to do so, or a United States citizen or
       an alien admitted for permanent residence in the
       United States who travels in foreign commerce,
       or conspires to do so, for the purpose of engag-
       ing in any sexual act (as defined in section 2246)
       with a person under 18 years of age that would
       be in violation of chapter 109A if the sexual act
       occurred in the special maritime and territorial
       jurisdiction of the United States shall be fined
       under this title, imprisoned not more than
       15 years, or both.
18 U.S.C. § 2423(b) (effective Oct. 30, 1998 to Nov. 1, 2002).
Stokes focuses on the phrase “sexual act … with a person
under 18 years of age that would be in violation of
chapter 109A.” He claims that this cross-reference renders the
statute unconstitutionally vague because some of the crimes
listed in chapter 109A (18 U.S.C. §§ 2241–2244) involve victims
under the age of 16, making the age requirements contradic-
tory and confusing.
    Stokes’s vagueness challenge sounds in the Fifth Amend-
ment’s guarantee of due process. “A conviction or punishment
fails to comply with due process if the statute or regulation
under which it is obtained ‘fails to provide a person of ordi-
nary intelligence fair notice of what is prohibited … . ’ ” FCC v.
Fox Television Stations, Inc., 132 S. Ct. 2307, 2317 (2012) (quoting
United States v. Williams, 553 U.S. 285, 304 (2008)); see also
United States v. Jones, 689 F.3d 696, 701 (7th Cir. 2012) (“Vague-
ness doctrine rests on concerns about fair notice and arbitrary
enforcement.”); United States v. Plummer, 581 F.3d 484, 488 (7th
No. 11-2734                                                               25

Cir. 2009) (A statute is unconstitutionally vague if it “ ‘does not
provide a person of ordinary intelligence a reasonable oppor-
tunity to know what is prohibited.’ ” (quoting United States v.
Lim, 444 F.3d 910, 915 (7th Cir. 2006))).
    With respect to the intended victim’s age, the version of
§ 2423(b) under which Stokes was convicted has two basic
requirements: (1) the sought-after victim must be a person
under 18 years of age; and (2) the intended conduct must
qualify as an offense under chapter 109A if the conduct had
taken place within the special maritime and territorial jurisdic-
tion of the United States. Chapter 109A creates a series of sex
crimes, some of which do not contain victim-age requirements
at all and some of which pertain only to minor victims under
the age of 16. For example, under 18 U.S.C. § 2241(a), which
defines aggravated sexual assault, it is a federal crime to cause
another to engage in a sexual act by the use of force or threat
if the conduct occurs in the special maritime and territorial
jurisdiction of the United States. Section 2241(c), a different
subsection of the same statute, criminalizes sexual acts with a
person under the age of 12 within the same jurisdictional
limits. Under § 2243(a) it is a federal crime to engage in a
sexual act with a person older than 12 but younger than 16
within the same jurisdictional limits if the perpetrator is at least
four years older than the victim.4
   The cross-reference, though perhaps awkwardly phrased,
does not introduce confusion. Together, § 2423(b) and the


4
  There are other crimes listed in chapter 109A, but they are not relevant to
Stokes’s argument.
26                                                            No. 11-2734

crimes listed in chapter 109A criminalize interstate and foreign
travel undertaken for any of the following purposes: (1) engag-
ing in a sexual act with a minor under the age of 12, see
§ 2241(c); (2) engaging in a sexual act with a minor between the
ages of 12 and 16 if the perpetrator is at least four years older
than the victim, see § 2243(a); and (3) engaging in a sexual act
with a minor between the ages of 16 and 18 by the use of force
or threat, see § 2241(a). The statute is not unconstitutionally
vague.5


     3. Evidentiary Claims
        i. Other-acts evidence under Rules 404(b), 413, and 414
   Stokes objects to the admission at trial of his 2000 Florida
conviction for molesting two boys and the testimonial and


5
  Stokes also argues that the indictment was unconstitutionally vague. The
indictment closely tracked the language of 18 U.S.C. § 2423(b), so this
argument overlaps with the challenge to the statute. Because the statute is
not unconstitutionally vague, the indictment isn’t either. And the indict-
ment was otherwise legally sufficient. An indictment

        must accomplish three functions: [I]t must state each of the
        elements of the crim e charged; it must provide adequate
        notice of the nature of the charges so that the accused may
        prepare a defense; and it must allow the defendant to raise
        the judgment as a bar to future prosecutions for the same
        offense.

United States v. Fassnacht, 332 F.3d 440, 444–45 (7th Cir. 2003). The indict-
ment met these requirements. Finally, the district court gave the jury clear
instructions on the age-of-victim issue as it pertained to the facts of this
case.
No. 11-2734                                                      27

photographic evidence of his sexual abuse of Thai boys. The
district court allowed this evidence as proof of Stokes’s intent
in traveling to Thailand, as is permitted under Rule 404(b) of
the Federal Rules of Evidence. The district court also admitted
the evidence under Rules 413 and 414, which expressly permit
the introduction of the defendant’s prior acts of sexual assault
or child molestation in a prosecution for sexual assault or child
molestation.
    Stokes first claims that Rules 413 and 414 are unconstitu-
tional under the Due Process Clause and the equal-protection
component of the Fifth Amendment. We have already rejected
this argument, see United States v. Julian, 427 F.3d 471, 487 (7th
Cir. 2005), as has the Tenth Circuit, see United States v. Castillo,
140 F.3d 874, 883 (10th Cir. 1998). We see no reason to revisit
the issue here.
    Stokes also insists that the other-acts evidence was admitted
in violation of Rule 404(b). This argument is frivolous. Stokes’s
sexual abuse of young boys both before and after his travel to
Thailand was directly and centrally relevant to his intent at the
time of his travel, an element of the crime and a permitted
purpose for the admission of other-acts evidence under
Rule 404(b). See FED . R. EVID . 404(b)(2) (other-acts evidence
“may be admissible for [a nonpropensity] purpose, such as
proving motive, opportunity, intent, preparation, plan,
knowledge, identity, absence of mistake, or lack of accident”).
Indeed, Stokes’s intent was the key disputed issue at trial. If
that were not enough, as we have noted, Rules 413 and 414
expressly permit the introduction of prior acts of sexual assault
or sexual molestation in a prosecution for sexual assault or
28                                                    No. 11-2734

sexual molestation, overriding the propensity bar in Rule 404(a)(1).
    Moreover, in a case quite similar to this one involving a
§ 2423(b) prosecution, we have upheld the admission of the
defendant’s past acts of child molestation under Rules 404(b),
413, and 414. See United States v. McGuire, 627 F.3d 622, 626–27
(7th Cir. 2010) (holding that “[t]he testimony [of the child
victims] was admissible as evidence of the defendant’s modus
operandi (and thus not excludable under Rule 404(b) of the
Federal Rules of Evidence), and it was also admissible under
Rules 413 and 414 as evidence of the defendant’s previous
crimes” (citation omitted)). We have also upheld the admission
of the defendant’s past acts of child molestation to show
motive in child-pornography cases. See, e.g., United States v.
Russell, 662 F.3d 831, 846–47 (7th Cir. 2011) (holding that prior
molestation was allowed under Rule 404(b) to show defen-
dant’s motive in taking obscene photographs of children);
United States v. Sebolt, 460 F.3d 910, 917 (7th Cir. 2006) (holding
that prior acts of sexual misconduct with a child are admissible
to establish defendant’s sexual interest in children and motive
under Rule 404(b)).
    Finally, this evidence was not unfairly prejudicial to Stokes
under Rule 403. The government limited its photographic
evidence to 20 representative images and presented the
testimony of only two of Stokes’s many victims.


       ii. Evidence of Stokes’s changed lifestyle
   Stokes sought to introduce evidence that he dramatically
changed his lifestyle following the search of his home in 2003.
No. 11-2734                                                    29

Recall that three years passed between the October 2003 search
and Stokes’s arrest in 2006. Stokes wanted to testify that during
this time, he got married, moved to a different area of Thai-
land, held a respectable position in a university, and estab-
lished strong relations with his wife’s family. The district court
excluded this evidence as irrelevant. This ruling was sound.
Any change in Stokes’s ways after October 2003 was utterly
irrelevant to his purpose in traveling to Thailand in March 2000
and January 2002.


   4. Sufficiency of the Evidence
    Stokes next claims that the government’s evidence was
insufficient to convict him. This argument is frivolous. A
defendant challenging the sufficiency of the evidence faces an
intimidating standard of review. We ask only “whether after
reviewing the evidence in the light most favorable to the
prosecution, any rational trier of fact could have found the
essential elements of the crime beyond a reasonable doubt.”
Jackson v. Virginia, 443 U.S. 307, 319 (1979). Stokes plows ahead
undeterred, arguing that the evidence was insufficient because
it “only established a general propensity to engage in illicit
sexual activity” and did not “in any way speak to his specific
intent on the relevant date” of his travel.
    The illicit purpose of Stokes’s travel was unmistakably
established by the abundant evidence of what he did before
and after the travel. Immediately after being convicted of
misdemeanor battery for molesting two young boys in Florida,
he sought and received permission to move to Thailand. Less
than a month later he made the move, and within two weeks
30                                                    No. 11-2734

of arriving in Thailand, began enticing young Thai boys for
sex. This activity continued unabated for three years, with a
brief hiatus for a three-week trip to the United States in
December 2001. His return trip to Thailand in January 2002
was marked by an immediate resumption of his sexual activity
with young Thai boys. The evidence was overwhelming and
easily sufficient to convict Stokes under § 2423(b).


     5. Ineffective Assistance of Counsel
    Stokes also argues that his counsel had insufficient time to
prepare for trial and was constitutionally ineffective. Chal-
lenges to trial counsel’s performance are best brought on
collateral review rather than direct appeal. See Massaro v.
United States, 538 U.S. 500, 504–05 (2003) (“When an ineffective-
assistance claim is brought on direct appeal, appellate counsel
and the court must proceed on a trial record not developed
precisely for the object of litigating or preserving the claim and
thus often incomplete or inadequate for this purpose.”). Stokes
raised the issue of counsel’s ineffectiveness in an underdevel-
oped argument on motions after verdict. The district court
denied relief, and Stokes asks us to address the issue now. We
can’t think of a good reason for that strategy. “Circuit law is
clear … that a ‘defendant who complains on direct appeal
about the quality of his lawyer can’t try again on collateral
attack unless there has been an intervening change of law.’ ”
Peoples v. United States, 403 F.3d 844, 846 (7th Cir. 2005)
(quoting Ryan v. United States, 214 F.3d 877, 879 (7th Cir. 2000)).
We think it best to leave the issue for collateral review.
No. 11-2734                                                    31

   6. Sentencing Arguments
    In the first of several sentencing arguments, Stokes claims
that the district court erred by increasing his offense level
under U.S.S.G. § 2G2.1(b)(1)(A) because some of his victims
were under 12 years old. This argument, based on Apprendi v.
New Jersey, 530 U.S. 466, 490 (2000), is frivolous and has been
for some time. The argument “ignores the effect that [United
States v. Booker, 543 U.S. 220 (2005)] had on federal sentencing.”
United States v. White, 472 F.3d 458, 464 (7th Cir. 2006). Because
Booker rendered the sentencing guidelines advisory, “sentenc-
ing enhancements need not be found by a jury beyond a
reasonable doubt because they no longer alter the statutory
maximum.” Id. Stokes also relies on United States v. O’Brien,
130 S. Ct. 2169 (2010), but we cannot tell why. O’Brien involved
a statutory penalty provision.
   Stokes also objects to the imposition of a guidelines
adjustment for obstruction of justice under U.S.S.G. § 3C1.1. He
has misunderstood the district court’s guidelines calculation.
The court did not in fact apply the obstruction adjustment
because with or without it, Stokes’s advisory guidelines range
was life, exceeding the statutory maximum of 15 years.
    Finally, Stokes’s sentence is unaffected by the Supreme
Court’s recent decision in Peugh v. United States, 133 S. Ct. 2072
(2013). To calculate Stokes’s advisory sentencing range, the
district court used the 2010 guidelines manual in effect at the
time of sentencing. This approach was consistent with then-
existing circuit precedent. See United States v. Demaree, 459 F.3d
791 (7th Cir. 2006). In Peugh, however, the Supreme Court
abrogated Demaree.
32                                                    No. 11-2734

    Peugh addressed “whether there is an ex post facto violation
when a defendant is sentenced under Guidelines promulgated
after he committed his criminal acts and the new version
provides a higher applicable Guidelines sentencing range than
the version in place at the time of the offense.” 133 S. Ct. at
2078. The Court held that “[a] retrospective increase in the
Guidelines range applicable to a defendant creates a sufficient
risk of a higher sentence to constitute an ex post facto violation.”
Id. at 2084. But the Court also noted that an ex post facto error
may be harmless in “cases in which the record makes clear that
the District Court would have imposed the same sentence
under the older, more lenient Guidelines tha[n] it imposed
under the newer, more punitive ones.” Id. at 2088 n.8.
    The parties submitted supplemental briefs on the effect of
Peugh on Stokes’s sentence. They agree that the adjusted
offense level would have been lower under the guidelines in
effect in 2002, the time of Stokes’s last travel to Thailand. But
even with the reduced offense level, the advisory guidelines
range would have been 210 to 262 months, still well above the
statutory maximum of 15 years.
   Moreover, the district judge made it abundantly clear that
she would impose the 15-year maximum no matter what the
guidelines advised her to do:
          I am of the view that nothing short of the
       maximum penalty is appropriate here. I am
       imposing a sentencing of 180 months, which is
       what the statute calls for.
       ….
No. 11-2734                                                33

         I am satisfied that Mr. Stokes needs to be
      separated from society for as long as I have it in
      my power to do that. 180 months.
    The judge could not have been clearer. Accordingly, Peugh
does not affect this case for two reasons. Stokes’s sentencing
range exceeded the statutory maximum no matter which
guidelines manual applied, so Stokes never actually faced a
“retrospective increase in the Guidelines range applicable to
[him].” Id. at 2084. And because the judge would have imposed
the statutory maximum regardless, any arguable ex post facto
error was harmless.
                                                   AFFIRMED .
