Out of Pod Experience

I made my own tinfoil hat

If tinfoil really blocked out signals....then were all the people who used it on their TV antennas (back when TVs HAD antennas) really making the reception worse?

Actually, tinfoil would be quite effective at shielding against EM radiation (not sure about gamma rays - those have a pretty high wavelength). Regardless, the whole original tinfoil hat thing is based in the principles of a Faraday cage which is based on the principle that the net electric field inside a closed conductor is always zero. You would have to ensure, obviously, that it were a fully closed conductor. Wire mesh is preferable to prevent asphyxiation. If you believe EM radiation can read your thoughts, asphyxiation in tinfoil is a serious concern.

Regardless, it should always be noted that wherever there exists an abundance of an ideologial chacterization of something, esecially in the form of a straw man argument, such as the infamous tinfoil hat cliche, there most likely has been a demand which precipitated that. For example, religious extremism thrives in impoverished areas because people lack hope and religious convictoin supplies that demand. Tin foil hat straw men exist where there are conspiracies because there's a demand to deflect attention from it.

CIA Operative Elizabeth Hanson did some rare work on the supply and demand of ideological premises - she was murdered by a double-agent. Tinfoil hats will not protect you when they really want you gone.