"The leaders of these active clubs also maintain connections with several pre-existing far-right groups, some of whom have perpetrated hate crimes. 'Violence is the underlying feature of all of this,' said Joshua Fisher-Birch, an analyst for the Counter Extremism Project, a non-profit that combats extremist groups. 'If you're training people in combat sports in this capacity, it seems like a matter of time before someone is going to use that against someone else.'"