By 1942 the FBI was adding 400,000 file cards a month to its archives, and were receiving 110,000 requests for “name checks” per month. By 1944 the agency contained some 23 million card records, as well as 10 million fingerprint records. Around the war, the federal government invested huge resources into the FBI to investigate potential defectors and spies. President Roosevelt, for one, was concerned about the lure of Communism and the subsequent threat to democracy. By the end of 1943, the FBI employed around 13,000 people.
The FBI once sent a letter to MLK trying to convince him to commit suicide
On November 21, 1964, a package that contained the letter and a tape recording allegedly of King’s sexual indiscretions was delivered to Coretta Scott King, and later to Martin Luther King Jr. Although the letter was anonymously written, Martin Luther King Jr. correctly suspected the FBI sent the package.