As I understand it, the tin foil is to reflect away the Orbital Mind Control Lasers, so it doesn't need to be a Faraday cage. It only needs to be on top of your head (ideally with some overhang) because the satellites are in the sky, which is above you, right? I'm guessing from this either that the lasers can't penetrate the greater thickness of atmosphere to target you from a lower point in the sky, or that believers in this conspiracy have a less than firm grasp of orbital mechanics. But what do I know, my understanding of the subject comes entirely from playing Illuminati...
(no subject)