Tinfoil hat
From RationalWiki
The tinfoil hat is a sort of mocking symbol of paranoia and conspiracy theory advocacy, derived by the use of some paranoid schizophrenics with persecution and mind control delusions of aluminum foil hats to protect them from perceived mind control rays.
The term came about because of serious suggestions by true believers that constructing a simple hat out of aluminum foil could protect their brains from being bombarded with mind control rays or whatever it was they were paranoid about. The idea was so laughable that it quickly took on a life of its own as a sarcastic way of referring to any especially preposterous notion that usually involves a mixture of paranoia with pseudoscience.
- "And just because someone else also has a tinfoil hat on doesn't make yours any less shiny." --Gulik pwning TmtamesP[1]
[edit] Advanced scientifical forms
Some claim that copper mesh works better. Personally, I prefer a zinc-manganese alloy in a bilayered hexagonal array.
In 2005 a group of engineering and media students at MIT performed attenuation versus frequency measurements for different tinfoil hat designs, concluding that the hats actually increased the intensity of RF energy at certain frequencies, with the implication that the tinfoil hat fad was actually a government plot to increase the effectiveness of mind control rays. [2] Of course the government could have blackmailed the MIT students to write that false report to make you take off your tinfoil so they can effect you with mind control rays. Then again the government could also be blackmailing me to write this so you will keep your tinfoil cap on to better amplify the mind control rays.
[edit] See also
Other terms that have taken on a life of their own in the same way, for similar reasons, include:

