Prior to 1976, national security investigations at the FBI followed no specific guidelines established by either the Department of Justice or Congress. Without oversight, the agency developed a covert Counterintelligence Program (COINTELPRO) to target the Communist Party U.S.A. During its lifespan from 1956 to 1971, the program involved aggressive and illegal tactics to harass, disrupt, discredit, and collect intelligence on the party and its members. COINTELPRO's purpose was to protect national security, prevent violence, and maintain the social and political order in the United States. It was not designed to build traditional cases to be brought to trial. The FBI expanded COINTELPRO to target groups and movements such as the Socialist Workers Party, the Ku Klux Klan, the New Left, and the Black Panther Party. The program was developed partly because the FBI was frustrated with the U.S. Supreme Court limits on overt investigations of dissident groups.
With COINTELPRO, the FBI "took the law into its own hands" and authorized questionable methods including "use of subterfuge, plant[ing] agents provocateurs, [and] leak[ing] derogatory information to the press." Among specific tactics, the FBI mailed anonymous letters to break up marriages, contacted employers to get people fired from their jobs, and falsely declaimed individuals as government informants to discredit them within their own organizations. The agency even targeted some nonviolent organizations, such as the Southern Christian Leadership Conference, because it "believed they represented a 'potential for violence.'" As the FBI itself acknowledges, some COINTELPRO methods were excessive and "went too far for the American people."
The public first learned of the program after a 1971 burglary at an FBI office in Media, PA. Individuals tied to the incident leaked information on COINTELPRO to the press and Congress. In response, the FBI terminated the program.