It will be if Patriot Act II: The Search For More Power becomes law:
Section 501, Expatriation of Terrorists: This provision, the
drafters say, would establish that an American citizen could be
expatriated if, with the intent to relinquish his nationality, he
becomes a member of, or provides material support to, a group that the
United Stated has designated as a terrorist organization. But
whereas a citizen formerly had to state his intent to relinquish his
citizenship, the new law affirms that his intent can be inferred from
conduct. Thus, engaging in the lawful activities of a group designated
as a terrorist organization by the Attorney General could be
presumptive grounds for expatriation.
Anybody want to place bets that the ACLU will considered a group that supports terrorists? Anybody want to join up anyway?