Cointelpro stands for Counter Intelligence Program. It was a program started by the Federal Bureau of Investigation (FBI) in the 1950's and 1960's. It was designed to stop people who were trying to make changes to the government of the United States, like civil rights and anti-war activists. The FBI used agents to look for and collect information on these activists, including their personal information and even their private conversations. They used this information to try to stop the activists from succeeding, like by planting false information, spreading rumors, and even harassing and threatening them. All of these things were done in secret, so the activists didn't even know the FBI was behind it. This was wrong, and it was stopped in the 1970's.