[Valin]

Back during the 60's and early 70s about 1/2 the members of the Socialist Workers Party were FBI/LEO. When the Viet-Nam war ended their membership plummeted.
I've heard tales of members of the "anti-war" groups having to stop plots to blow something up when they discovered they were all FBI agents.

[Kurt_D]

What about the International Socialist Organization, a bunch of Trotskist who are very active on university campuses, but are virtually unnoticed anywhere else. I am sure that some of those full-time revolutionaries/long-term students must be some sort of undercover agents. Have you ever read the Socialist Worker? It's just way too flamboyant to take it seriously.

[Strategerist]

I've heard about 1/2 the members of the Ku Klux Klan these days are FBI undercovers...