Among those Americans held by foreign governments is Trevor Reed, a Marine veteran who was sentenced in Russia to nine years on charges he assaulted a police officer.
Malik Faisal Akram was heard demanding the release of a Pakistani neuroscientist who was convicted of trying to kill U.S. Army officers in Afghanistan.
Jonathan Toebbe is accused of passing on design information about sophisticated Virginia-class submarines to someone he thought represented a foreign government but who was actually an undercover FBI agent.
A Navy nuclear engineer with access to military secrets has been charged with trying to pass information about the design of American nuclear-powered submarines, according to the Justice Department.