It is led by the same branch of career revolutionaries that brought us the pro-NVA "peace" movement during the Vietnam War: The Communist Party USA, the Socialist Worker's Party, and the International Workers of the World (anarchists).
The FBI used to be mildly interested in discovering who was in charge, who was getting the money, where the safe houses/communications networks were - and who was trying to kill people - but today's FBI is more allied with them to actually investigate them.
We're on our own.