Three letter agencies have a long, colorful history of influencing the landscape of politics in the US. Let's talk about COINTELPRO, a massive undertaking by the united states government to control the political narrative that is still ongoing in different forms today.
COINTELPRO operations stretch all the way back to 1956, originally designed to split up the blooming communist party that was a rising influence in the political landscape at the time. Soon after, the umbrella of the operation was extended to include prominent black leaders, the justification being that those movements were being infiltrated by the communist threat.
The term itself stands for counter intelligence program, but is used to refer to a wide collection of illegal covert projects aimed at keeping tabs on political groups, as well as infiltrating, discrediting, and steering the agenda of said groups.
Such groups include anti-vietnam organizers, civil rights groups, feminist groups, and more recently, BLM. When the FBI deems a group to be subversive to the 'official narrative', they pay people to join these groups and disrupt the inner workings to dismantle the cause at the source.
Presidential figures have been implicated in these dealings; Herbert Hoover directed the FBI to comb through Martin Luther King's life for anything that might discredit him, for example.
The original program was kept under wraps until 1971, when an FBI office was burgled and several dossiers relating to the operation were leaked to the media. Shortly after that, Hoover came out and announced that the program was over, and that future counter intelligence operations would be on a 'case by case basis'.
Reports coming out related to the program since those days are often entirely blacked out.
The original incarnation of domestic counter intelligence projects may be dead, but the techniques pioneered in those days are alive and well in today's political landscape. The internet has made it easier than ever to change the perceptions of the public; such is the idea behind organizations like 'Correct The Record', a political superpac that hired hundreds of thousands of users to brigade forums and social media with specific directed messages during the 2016 US elections.