adj. - having characteristics in common with paranoid delusions. The word comes from paranoid people wearing tinfoil hats to keep the aliens from reading their mind, or to keep the Illuminati from using mind control rays on them, etc.
"You have to sign this petition! It's to get Congress to require all envelopes to be self-adhesive. When you lick an envelope flap, the Post Office runs it through a scanner that takes a DNA sample. Then they match that up with your name based on the return address. Homeland Security claims to be keeping the information to know how best to protect Americans from a gene-based terrorist attack, but if the wrong people came into power, they could use it for eugenics and put everyone with a certain chromosome combination into concentration camps! So will you sign the petition?"
"Um...I don't know, dude. Sounds a little tinfoily to me."