Disloyalty to the US.
Iva Toguri D'Aquino ("Tokyo Rose," convicted 1949): U.S. citizen of Japanese descent stranded in Japan. She broadcast English-language radio propaganda for Japan aimed at U.S. troops (e.g., undermining morale by referencing ship losses). Charged with adhering to Japan and giving aid/comfort through broadcasts. Convicted on one count; served ~6 years of a 10-year sentence and fined. (Later pardoned by President Ford in 1977 after evidence of perjured testimony emerged; many view it as a miscarriage of justice driven by public pressure.)
Adam Gadahn (indicted 2006, not tried): U.S. citizen who joined al-Qaeda and appeared in propaganda videos praising 9/11, threatening attacks, and urging Americans to join the enemy. Indicted for treason (adhering to al-Qaeda and giving aid/comfort via propaganda) plus material support. First treason charge since WWII era; killed in a 2015 drone strike before trial.
