Check out this piece by some MIT researchers on the government mind control plot. They tested aluminum hats to see if they indeed protect the brain from goverment mind control transmissions.
It turns out instead of blocking frequencies, the hats actually improve reception for some government-controlled frequency ranges.
Hmmm? . . . I wonder? . . . Did governmet operatives spread the idea of putting on the aluminum hats, so they could control us? Dang. You just can't keep the conspiracy theories from continuing to spin.