Context: The FBI has maintained files on numerous people, including celebrities such as Elvis Presley, Frank Sinatra, John Denver, John Lennon, Jane Fonda, Groucho Marx, Charlie Chaplin, the band MC5, Lou Costello, Sonny Bono, Bob Dylan, Michael Jackson, and Mickey Mantle. The files were collected for various reasons. Some of the subjects were investigated for alleged ties to the Communist party (Charlie Chaplin and Groucho Marx), or in connection with antiwar activities during the Vietnam War (John Denver, John Lennon, and Jane Fonda). Numerous celebrity files concern threats or extortion attempts against them (Sonny Bono, John Denver, John Lennon, Elvis Presley, Michael Jackson, Mickey Mantle, Groucho Marx, and Frank Sinatra).

Question: Did the FBI keep files on Elvis Presley?
Answer: including celebrities such as Elvis Presley

Question: What activities was the FBI concerned with during the Vietnam war?
Answer: antiwar activities

Question: What kinds of treats were celebrities receiving?
Answer: threats or extortion attempts

Question: What party was the FBI concerned with?
Answer: Communist party

Question: Who has the FBI never maintained a file on?
Answer: Unanswerable

Question: Who was investigated due to ties with the Libertarian party?
Answer: Unanswerable

Question: Who was investigated for pro war activity?
Answer: Unanswerable

Question: Who is a celebrity that did not have threats against them?
Answer: Unanswerable

Question: Who is a celebrity that the CIA has a file on?
Answer: Unanswerable