                          In the
 United States Court of Appeals
              For the Seventh Circuit
                       ____________

No. 06-1385
UNITED STATES OF AMERICA,
                                          Plaintiff-Appellee,
                             v.

NING WEN,
                                      Defendant-Appellant.
                       ____________
         Appeal from the United States District Court
             for the Eastern District of Wisconsin.
        No. 04-CR-241—William C. Griesbach, Judge.
                       ____________
 ARGUED OCTOBER 20, 2006—DECIDED DECEMBER 14, 2006
                    ____________


 Before EASTERBROOK, Chief Judge, and BAUER and
EVANS, Circuit Judges.
  EASTERBROOK, Chief Judge. A jury found Ning Wen
guilty of violating the export-control laws by providing
militarily useful technology to the People’s Republic of
China without the required license. See 50 U.S.C.
§1705(b). He has been sentenced to 60 months’ imprison-
ment. His only argument on appeal is that the district
court should have suppressed evidence derived from a
wiretap approved under the Foreign Intelligence Sur-
veillance Act. After reviewing the materials in camera,
the judge concluded that the intercept order was amply
justified and denied this motion.
2                                               No. 06-1385

  As enacted in 1978, FISA applied to interceptions the
“primary purpose” of which was foreign intelligence; as
amended in 2001 by the USA PATRIOT Act, the statute
applies to interceptions that have international intelli-
gence as a “significant purpose”. 50 U.S.C. §1804(a)(7)(B).
The Foreign Intelligence Surveillance Court of Review has
concluded that the amended statute allows domestic use
of intercepted evidence as long as a “significant” interna-
tional objective is in view at the intercept’s inception.
Sealed Case, 310 F.3d 717 (F.I.S. Ct. Rev. 2002). Wen asks
us to disagree with that decision and hold that evidence
gathered under FISA cannot be used in domestic criminal
investigations or prosecutions, even when the “domestic”
crime is linked to international espionage, once that
international investigation has “fizzled out” (Wen’s
phrase).
  The principal problem with Wen’s argument is that the
exclusionary rule is used to enforce the Constitution, not
statutes or regulations. See United States v. Caceres, 440
U.S. 741 (1979). So even if Wen is right about the mean-
ing of FISA, there is no basis for a district court to reject
evidence that was properly gathered. (Like the district
court, we have reviewed the affidavits in camera and
conclude that the statutory standards for an intercept
order are satisfied.) Legislation may provide for enforce-
ment via exclusion; Title III of the Omnibus Crime Con-
trol and Safe Streets Act of 1968, the principal statute
regulating domestic wiretaps, does just that. See 18
U.S.C. §2518(10)(a); United States v. Donovan, 429 U.S.
413 (1977). FISA lacks any comparable provision. So unless
there is a constitutional problem in domestic use of
evidence seized as part of an international investigation,
there is no basis for suppression.
  As it happens, moreover, there is scant support for
suppression even when a particular intercept is unrea-
sonable under the fourth amendment. For each intercept
No. 06-1385                                               3

must be authorized by a warrant from a federal district
judge. See 50 U.S.C. §1803(a). This brings into play the
rule of United States v. Leon, 468 U.S. 897 (1984), that the
exclusionary rule must not be applied to evidence seized
on the authority of a warrant, even if the warrant turns
out to be defective (say, because not supported by prob-
able cause), unless the affidavit supporting the warrant
was false or misleading, or probable cause was so trans-
parently missing that “no reasonably well trained officer
[would] rely on the warrant.” Id. at 923.
  At one time it was seriously questioned whether an
intercept order is a “warrant” for constitutional purposes,
see Telford Taylor, Two Studies in Constitutional Interpre-
tation 79-88 (1969), but characterization was settled in
favor of “warrant” status by Dalia v. United States, 441
U.S. 238, 256 n.18 (1979). And our in camera review
reveals that well-trained officers were entitled to rely on
this warrant. The Executive Branch did the right thing
in asking for a warrant. Suppose that FISA was the wrong
source of authority and the judge had turned the request
down because the investigation’s domestic component
overshadowed its international aspect. Then the Executive
Branch could have obtained a domestic intercept order
under Title III. The evidence narrated in the affidavit
establishes probable cause to believe that phone lines
were being used to discuss or plan violations of 50 U.S.C.
§1705(b). A statutory error about which court should have
issued a warrant, and under which statute, does not
support exclusion.
  The only plausible constitutional objection to the war-
rant actually issued is that FISA uses a definition of
“probable cause” that does not depend on whether a
domestic crime has been committed. Under 50 U.S.C.
§1805(a)(3), an order may be based on probable cause
to believe that the target is an agent of a foreign power
and that the conversations to be intercepted concern the
4                                               No. 06-1385

agent’s dealings with that foreign power; the judge need
not find probable cause to believe that the foreign agent
probably is violating the law of this nation (although this
may be implied by the findings that FISA does require).
  Yet we know from the administrative-search cases that
the “probable cause” of which the fourth amendment
speaks is not necessarily probable cause to believe that
any law is being violated. The Court held in Camara v.
Municipal Court, 387 U.S. 523 (1967), and See v. Seattle,
387 U.S. 541 (1967), that municipal officials may not
barge into homes or businesses to look for violations of
the housing code; they must have warrants, which may
issue on probable cause to believe that the city has
adopted a reasonable system of inspections and is not
targeting citizens for irregular or malicious reasons.
Similarly, Marshall v. Barlow’s, Inc., 436 U.S. 307 (1978),
holds that, although federal inspectors need warrants to
inspect business premises for violations of the Occupa-
tional Safety and Health Act, these warrants may issue on
probable cause to believe that the agency is implement-
ing a reasonable system of inspections that includes the
business in question. Inspectors lawfully on the premises
under such warrants may report any violations of law
that they find; evidence in plain view need not be over-
looked, even if that evidence concerns a different statute.
   These principles carry over to FISA. Probable cause to
believe that a foreign agent is communicating with his
controllers outside our borders makes an interception
reasonable. If, while conducting this surveillance, agents
discover evidence of a domestic crime, they may use it to
prosecute for that offense. That the agents may have
known that they were likely to hear evidence of domestic
crime does not make the interception less reasonable than
if they were ignorant of this possibility. Justice Stewart’s
position that the plain-view doctrine is limited to “inadver-
tent” discoveries, see Coolidge v. New Hampshire, 403 U.S.
No. 06-1385                                              5

443, 469-71 (1971), has not carried the day. In Horton v.
California, 496 U.S. 128 (1990), the Court held that
evidence in plain view may be seized without a warrant
even though the police expected to find it. Likewise
evidence of a domestic crime, acquired during an inter-
cept that is reasonable because it concerns traffic between
a foreign state and one of its agents in the United States,
may be used in a domestic prosecution whether or not
the agents expected to learn about the domestic offense.
It is enough that the intercept be adequately justified
without regard to the possibility that evidence of domestic
offenses will turn up. Interception of Wen’s conversa-
tions was adequately justified under FISA’s terms, so there
is no constitutional obstacle to using evidence of any
domestic crimes he committed.
                                                AFFIRMED

A true Copy:
      Teste:

                       ________________________________
                       Clerk of the United States Court of
                         Appeals for the Seventh Circuit




                  USCA-02-C-0072—12-14-06
