(4)
to aid or abet any person in inciting or participating in or carrying on a riot or committing any act of violence in furtherance of a riot;
and who either during the course of any such travel or use or thereafter performs or attempts to perform any other overt act for any purpose specified in subparagraph (A), (B), (C), or (D) of this paragraph—
Shall be fined under this title, or imprisoned not more than five years, or both.