From SITE:
Adam Yahiye Gadahn AKA Adam Pearlman, Azzam al-Amriki (Azzam the American), has been charged with treason by a Grand Jury in an indictment filed today, Wednesday, October 11, 2006, in the State of California. According to the document, Gadahn has been indicted for treason, providing material support to a designated foreign terrorist organization, al-Qaeda, and aiding and abetting terrorists. The two counts against Gadahn are based on his appearances and statements made in al-Qaeda films produced and distributed by the organization’s multimedia arm, as-Sahab.
More...
Indictment (PDF - From SITE Institute)