On 21 March, the US Congressional Research Service published an updated briefing, saying that a number of US criminal laws apply extraterritorially outside of the US. Application is generally a question of legislative intent, express or implied. There are 2 exceptions. First, the statute must come within Congress’s constitutional authority to enact. Second, neither the statute nor its application may violate due process or any other constitutional prohibition. The CRS also issued an “Abbreviated Sketch” – an 8-page summary version.
https://crsreports.congress.gov/product/pdf/RL/94-166