## Facts

- A federal grand jury indicted Kent Frank, a U.S. citizen, on five counts under 18 U.S.C. § 2423(c) for engaging in “illicit sexual conduct” with under-18 females in Cambodia after traveling there from the United States between September 2003 and January 2004.
- Section 2423(c) criminalizes a U.S. citizen’s travel in foreign commerce followed by “illicit sexual conduct” abroad; as relevant here, “illicit sexual conduct” included any “commercial sex act” with a person under 18.
- The statute provides an affirmative defense if the defendant proves by a preponderance that he reasonably believed the person was at least 18.
- Frank moved pretrial to dismiss all counts, asserting that § 2423(c) was unconstitutional and inconsistent with international law when applied to conduct occurring entirely in Cambodia.
- The court’s ruling addressed only the validity of § 2423(c) as applied to commercial sex with minors abroad and did not adjudicate guilt.

## Issues

1. Whether Congress had constitutional authority (including under the Necessary and Proper Clause, foreign commerce power, and treaty-implementation power) to enact § 2423(c) as applied to a U.S. citizen’s commercial sex with minors abroad.
2. Whether § 2423(c) violates international law or impermissibly intrudes on foreign sovereignty where the host country’s age-of-consent rules allegedly differ.
3. Whether extraterritorial application of § 2423(c) to conduct in Cambodia violates the Fifth Amendment Due Process Clause due to lack of fair notice.

## Decision

- The court denied the motion to dismiss Counts 1–5.
- It held that, as applied to commercial sex (prostitution) with minors abroad, § 2423(c) is a valid exercise of congressional power under the Necessary and Proper Clause in aid of foreign commerce regulation and treaty implementation.
- It rejected the international-law challenge, concluding the United States may prescribe criminal rules for its nationals abroad and that the statute does not override foreign law.
- It rejected the due process challenge, finding the statute clearly provides extraterritorial notice by its text targeting travel in foreign commerce followed by illicit sexual conduct abroad.
- The court limited its analysis to commercial sex with minors and did not decide the statute’s validity in other applications.

## Legal Principles

- Congress may enact criminal statutes that apply extraterritorially when it clearly expresses that intent, including for conduct by U.S. citizens abroad.
- Under the Necessary and Proper Clause, legislation is valid if rationally related to executing an enumerated power, including implementing treaty obligations and regulating foreign commerce.
- International law permits a state to regulate and punish its nationals’ conduct abroad under the nationality principle; punishing a citizen in domestic courts does not, by itself, negate the host nation’s sovereignty.
- A due process “fair warning” challenge to extraterritorial criminal liability fails where statutory text clearly covers the conduct and the defendant is a U.S. citizen traveling in foreign commerce.

## Conclusion

The court upheld § 2423(c) against constitutional, due process, and international-law attacks and allowed prosecution to proceed on charges that a U.S. citizen traveled to Cambodia and engaged in commercial sex acts with minors, emphasizing treaty-implementation and nationality-based jurisdictional authority.


United States v. Frank, 486 F. Supp. 2d 1353 (S.D. Fla. 2007)