“Like the NSA, the FBI seems to have interpreted its terrorism-prevention mandate as license to collect and retain as much information as possible. It sweeps up massive amounts of information and retains it in giant databases—regardless of whether the information indicates any threat or wrongdoing. This broad collection and retention raises the same concerns about impacts on privacy and First-Amendment-protected activity as the NSA’s programs. In fact, in the case of the FBI, some of these concerns have already proved well-founded.”
Starting with J. Edgar Hoover’s well-known blackmail files used against his enemies.