From 1956 to 1971, the FBI ran a series of covert operations designed to infiltrate radical political groups. Dubbed COINTELPRO (for counterintelligence programs), it countenanced a wide variety of techniques for harassing and undermining groups by encouraging infighting and dissension.
The most ubiquitous technique was the poison pen letter, wherein an FBI agent posed as a member of a radical group. William C. Sullivan, perhaps J. Edgar Hoover’s most odious subordinate, was responsible for a great many of these; he’s believed to be the one behind the notorious letter urging Martin Luther King Jr. to commit suicide. This is only the most famous example, however; the FBI regularly did it to all of their target groups. They broke up Ku Klux Klan cells in the South by spreading rumors that chapter heads were sleeping with the wives of other members; through letters accusing Huey Newton and other leaders of being secret police informants, they fueled the suspicions and paranoia which ultimately doomed the Black Panthers.
The FBI’s most frequent target appears to have been the antiwar movement of the ’60s and ’70s, where the task was admittedly much easier. The movement was a fragile coalition in the best of circumstances, with radical groups like SDS clashing with mainstream liberal organizations over tactics and ideology, when they weren’t playing games of more-radical-than-thou with each other; they hardly needed J. Edgar Hoover’s encouragement to claw each others’ eyes out. But encourage them he did, with letters like this that are so transparent they shouldn’t have worked, except they aren’t markedly more absurd than the real thing:
Where are we headed? Oblivion, pal, that’s where. In the near future PL [Progressive Labor, a radical faction within SDS] will own SDS – lock, stock and jock – and those of us who really worked for the campus revolution will probably rejoin the plastic society for self-protection. PL is pushing into revolutionary ideology that borders on sheer insanity. Their worship of Chairman Mao – the Chinese George Wallace – as a divine being shows how sick they really are. To sum it up, kiddies, Mao sucks!
COINTELPRO was abruptly cancelled in 1971, after the burglary into the Media, Pennsylvania office by a radical left group exposed the program. It took several years, from the Church Committee’s investigation in the Senate to a series of press exposes based, in large part, to the Media disclosures. To this day it remains the most chilling example of the myriad ways the FBI abused it power to spy on, harass and disrupt American citizens.