Via Boing!Boing! is this fascinating site which reproduces letters sent to the FBI about Mad Magazine. Some of the letters want to know if the FBI considers Mad to be a communist publication, while others write to provide evidence that it is and demand the FBI crack down on the magazine (if there’s one thing the United States leads the world in, it’s busybody cranks).
I can just see HUAC asking people, are you now or have you ever been a reader of Mad Magazine?