                              In the

    United States Court of Appeals
                 For the Seventh Circuit
                     ____________________
No. 17-1327
UNITED STATES OF AMERICA,
                                                 Plaintiff-Appellee,

                                 v.

CORY S. CASTETTER,
                                             Defendant-Appellant.
                     ____________________

         Appeal from the United States District Court for the
           Northern District of Illinois, Fort Wayne Division.
      No. 1:14-CR-44-TLS — Theresa L. Springmann, Chief Judge.
                     ____________________

       ARGUED JUNE 2, 2017 — DECIDED AUGUST 4, 2017
                     ____________________

   Before FLAUM, EASTERBROOK, and KANNE, Circuit Judges.
    EASTERBROOK, Circuit Judge. With the authority of a war-
rant, see United States v. Jones, 565 U.S. 400 (2012), police in-
stalled and monitored a GPS locator on a car owned and
driven by Mark Holst. They were investigating Holst’s par-
ticipation in methamphetamine sales and wanted to know,
among other things, where he was getting the drug. The GPS
device had the ability to transmit data so that the car could
be traced in real time. Police tracked Holst’s car on Septem-
2                                                 No. 17-1327

ber 4, 2014, and learned that it had stopped at a particular
place for more than an hour. An informant told the police
that Holst had traveled to buy methamphetamine. Police
stopped Holst’s car as he was driving home and found some
of that drug. They relayed the information to other officers,
who applied for a warrant to search the house in whose
driveway Holst’s car had lingered. That house turned out to
be Cory Castetter’s. The search turned up methampheta-
mine, other drugs, and approximately $62,000 in cash.
    Prosecuted under federal law, 21 U.S.C. §841(a)(1),
Castetter moved to suppress the evidence found when the
police executed the second warrant. He did not dispute the
validity of the first warrant or the existence of probable
cause to support the second warrant, but he contended that
information derived from the first warrant should be ig-
nored—and, if it is ignored, the second warrant would lose
its foundation. Castetter observed that Holst lives in Michi-
gan, where the first warrant issued, while he lives just across
the border in Indiana. As Castetter saw things, Michigan’s
police lack authority to monitor the location of a car in Indi-
ana, no matter what the Michigan warrant says. Castetter’s
fallback argument is that the first warrant pertains to Holst,
not him, and that police (whether from Michigan or Indiana)
were forbidden to learn who was doing business on his
property without obtaining a warrant based on his own ac-
tivities. The district court rejected these arguments and de-
nied the motion. 115 F. Supp. 3d 968 (N.D. Ind. 2015). Castet-
ter then entered a conditional plea of guilty, reserving the
right to raise the suppression argument on appeal, and was
sentenced to 108 months’ imprisonment.
No. 17-1327                                                   3

    The problem with Castetter’s principal argument is that
the Fourth Amendment does not concern state borders. It
reads: “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 is-
sue, but upon probable cause, supported by Oath or afﬁr-
mation, and particularly describing the place to be searched,
and the persons or things to be seized.” Nothing there about
state lines. The Constitution demands that a warrant be sup-
ported by probable cause, an oath, and particularity. As we
have already mentioned Castetter does not deny that these
requirements were satisfied.
    States may decide as a matter of domestic law not to au-
thorize their police to acquire information extraterritorially,
but federal courts do not use the exclusionary rule to enforce
state-law doctrines. See Virginia v. Moore, 553 U.S. 164 (2008).
States also may elect to ignore information given to them, by
other states’ officers, about what happens within their terri-
tory. As far as the Fourth Amendment is concerned, the Indi-
ana judge who was asked to issue the second warrant could
have said: “I don’t think that the Michigan police have any
business insinuating their GPS locators into this state, so I
refuse to issue a warrant.” But the Indiana judge did not say
that. So we have not only the principle of Moore that viola-
tions of state law do not justify suppression in federal prose-
cutions, but also the (implicit) decision of the Indiana judge
that there was no problem, as a matter of Indiana’s law, in
using information about Indiana sent to police in Michigan.
   Information about Holst’s driving (and stopping) went
by radio to a receiver connected to the Internet. We do not
know the receiver’s location (it may have been a satellite or a
4                                                    No. 17-1327

cell-data node), but the Internet transcends state borders—
and the GPS satellites, all launched and operated by the U.S.
Air Force, are in orbit 12,540 miles high, well beyond any
state’s domain. The process of tracking a car’s location by
GPS does not offend any state’s sovereign rights; this prose-
cution cannot founder on the theory that the drug laws, or
the GPS system, exceed the national power to legislate, regu-
late, or investigate. Compare Bond v. United States, 134 S. Ct.
2077 (2014), with Gonzales v. Raich, 545 U.S. 1 (2005). The na-
tional government, not any state, regulates radio, interstate
computer networks, and the GPS system.
    Castetter’s fallback argument is equally weak. True, the
first warrant was not based on information about Castetter.
But neither did it authorize anyone to learn about the inside
of his home, as the infrared device did in Kyllo v. United
States, 533 U.S. 27 (2001). All the police learned by monitor-
ing the GPS device was the location of Holst’s car, and
Castetter lacked a privacy interest in that location.
    Suppose that instead of getting a warrant to track Holst’s
car, police had persuaded him to become an informant and
report what happened inside Castetter’s house. Suppose, in-
deed, that Holst had agreed to wear a camera and an audio
recorder, providing many facts about Castetter’s house and
comprehensive details about the transaction. That would not
have violated any of Castetter’s rights. See, e.g., Hoffa v. Unit-
ed States, 385 U.S. 293 (1966). Or suppose Castetter had given
Holst documents revealing specifics of his drug operations,
and the police later had stopped Holst without either proba-
ble cause or a warrant. Castetter could not object, because
the privacy invaded would have been Holst’s rather than
Castetter’s. See United States v. Payner, 447 U.S. 727 (1980);
No. 17-1327                                                5

Rawlings v. Kentucky, 448 U.S. 98 (1980). But the police did
none of these things. They obtained a location-tracking war-
rant and learned no more than where Holst had driven his
car. The Constitution is not offended if, by executing a war-
rant to search one person (such as Holst), police learn in-
criminating details about another (such as Castetter).
                                                   AFFIRMED
