"This report is based on a staff study of more than 20,000 pages of Bureau documents, depositions of many of the Bureau agents involved in the programs, and interviews of several COINTELPRO targets. The examples selected for discussion necessarily represent a small percentage of the more than 2,000 approved COINTELPRO actions. Nevertheless, the cases demonstrate the consequences of a Government agency's decision to take the law into its own hands for the 'greater good' of the country. COINTELPRO is the FBI acronym for a series of covert action programs directed against domestic groups. In these programs, the Bureau went beyond the collection of intelligence to secret action defined to 'disrupt' and 'neutralize' target groups and individuals. The techniques were adopted wholesale from wartime counterintelligence, and ranged from the trivial (mailing reprints of Reader's Digest articles to college administrators) to the degrading (sending anonymous poison-pen letters intended to break up marriages) and the dangerous (encouraging gang warfare and falsely labeling members of a violent group as police informers)."
Supplementary Detailed Staff Reports on Intelligence Activities and the Rights of Americans - Book III (1976)