The scope of [International Traffic in Arms Regulations]’s prohibition on speech could apply to members of the press republishing newsworthy technical data, professors educating the public on scientific and medical advances of public concern, enthusiasts sharing otherwise lawful information about firearms, domestic activists trading tips about how to treat tear gas or resist unlawful surveillance, and gun control opponents expressing a point about proliferation of weapons. Innocent online publication on certain topics is prohibited simply because a hostile foreign person could conceivably locate that information, use it to create something harmful, and use a harmful device against US interests. Speech cannot permissibly be repressed for such an attenuated and hypothetical government end.