Although the FBI's covert operations have been active throughout its history, the formal COunter INTELligence PROgram, or COINTELPRO, of the second half of the 20th century was centrally directed and targeted a range of political dissidents and organizations. The stated goals of COINTELPRO were to "expose, disrupt, misdirect, discredit, or otherwise neutralize" those persons or organizations that the FBI decided were "enemies of the State."
At its most extreme dimension, political dissidents have been eliminated outright or sent to prison for the rest of their lives. Many more, however, were "neutralized" by intimidation, harassment, discrediting, and a whole assortment of authoritarian and illegal tactics.
Neutralization, as explained on record by the FBI, didn’t necessarily pertain to the apprehension of parties in the commission of a crime, the preparation of evidence against them, and securing of a judicial conviction. Rather, the FBI simply made activists incapable of engaging in political activity by whatever means.
For those not assessed as being in themselves a security risk but engaged in what the Bureau viewed to be politically objectionable activity, those techniques consisted of disseminating derogatory information to the target's family, friends and associates, or visiting and questioning them. False information was planted in the press. The targets' efforts to speak in public were frustrated, and employers were contacted to try to get them fired. Anonymous letters accusing targets of infidelity were sent by the FBI to their spouses. Other letters contained death threats. These strategies are well-documented, for example, in the case of Rev. Martin Luther King, Jr. Records also show that activists in the 1960s were repeatedly arrested "on any excuse" until "they could no longer make bail."
In addition, the FBI made use of informants, often quite violent and emotionally disturbed individuals, to present false testimony to the courts and frame COINTELPRO targets for crimes the FBI knew they did not commit. In some cases the charges were quite serious, including murder.
Another option was "snitch jacketing" where the FBI made the target look like a police informant or an agent of the Central Intelligence Agency. This served the dual purposes of isolating and alienating important leaders, as well as increasing the general level of fear and factionalism in the group.
Many counterintelligence techniques involved the use of paid informants. Informants became "agent provocateurs" by raising controversial issues at meetings to take advantage of ideological divisions; promoting enmity with other groups; or inciting the group to violent acts, even to the point of providing them with weapons. Over the years, FBI provocateurs repeatedly urged and initiated violent acts, including forceful disruptions of meetings and demonstrations, attacks on police, bombings, etc.