In the last few years of his life, Ernest Hemingway grew paranoid and talked about FBI spying on him. He was even treated with electroshock therapy as many as 15 times at the recommendation of his physician in 1960. It was later revealed that he was in fact being watched, and Edgard Hoover had personally placed him under survelliance.
http://www.messynessychic.com/2013/06/18/10-things-you-probably-didnt-know-about-ernest-hemingway-like-he-was-a-kgb-spy/