Propoganda designed to cover up a massive government conspiracy. Begining in the late 1970's, the United States government tried to cover up its radio-wave thought-control program by circulating a false rumor that people could shield their minds from government intrusion by wearing a tinfoil hat. In truth, a tinfoil hat only improves reception and makes it easier for the government to read your mind. Speak truth to power!
Take off that tinfoil hat, you fool, the black helicopters are coming!