Cheap publicity stunt by Sullivan. The US government can't revoke Flashbang's citizenship at this point, because he hasn't
yet been convicted of a crime.
The law governing revocation of naturalized citizenship is
8 USC 1481. Paragraph a(7) states that a person must be
convicted of:
-committing any act of treason against, or attempting by force to overthrow, or bearing arms against, the United States, violating or conspiring to violate any of the provisions of section 2383 of title 18, or willfully performing any act in violation of section 2385 of title 18, or violating section 2384 of title 18 by engaging in a conspiracy to overthrow, put down, or to destroy by force the Government of the United States, or to levy war against them, if and when he is convicted thereof by a court martial or by a court of competent jurisdiction. In my opinion, it is unlikely the US Government will file to revoke his citizenship after conviction, because execution of the sentence (death or imprisonment) would not change if his citizenship is revoked.