(1) involve violent acts or acts dangerous to human life that are a violation of the criminal laws of the United States or of any State, or that would be a criminal violation:
(A) to intimidate or coerce a civilian population;
(B) to influence the policy of a government by intimidation or coercion; or
(C) to affect the conduct of a government by assassination or kidnapping; and
For non-terrorist armed para-military units, US Code requires such group register their leaders, contributors, activities and weapons.
See 18 U.S. Code § 2386. Registration of certain organizations. law.cornell.edu/uscode/text/18…