Although anit wi-fi paint isn't really a new concept the University of Tokyo had come out with a new much more powerful one. Here is a paint that when painted on your walls absorb frequencies transmitting at 100GHz. Basically no signal will get out of your house. So if you live in a area that you fear someone could be hacking your signal and maybe downloading something not so good from it then this might be the perfect answer for you.

Now one of the down sides is that it not only blocks your signal from going out but also blocks any signal from coming in. Yeah good luck getting that cell phone to ring or that radio to play.

They say this could be awesome for movie theaters to use then you wouldn't have to worry about the accidental cell phone that goes off in the movies. That might be great but I see a down side to that. Sometimes you can't turn off your cell (like if your on call or a parent out with a little one at home) and just going to vibrate is the answer. Personally I think I'll just make sure my router is secure, that's easier then repainting my house (and cheaper). Anyways you can read more here: clicky