In Policing Show Business, Francis MacDonnell explores the starring role played by J. Edgar Hoover in the development of the Hollywood blacklist in the 1940s and 1950s. As director of the FBI, Hoover poured resources into scrutinizing show business, a policy choice unjustified by any corresponding threat to public security. He detailed agents to write regular reports on actors, screenwriters, lyricists, singers, and studio executives. His...