That's right folks, the Japanese have spent some time perfecting anti-Wi-Fi paint. It's pretty simple and amazingly cool actually. You paint your walls - inside or outside, it doesn't really matter - with this paint and it keeps your wireless signal in so all those suckers outside can't download Madagascar 2 illegally on your wireless dime and your wireless address and your wireless responsibility. It will also, however, keep you from sponging off your neighbors' Wi-Fi connection, cheap ass.
The way it works is really cool. They have mixed imperceptibly small aluminum-iron oxide metal flecks into the paint, which resonate at the same frequency as do radio waves, meaning that the radio waves can't pass through. Any kind of radio waves. That includes Wi-Fi, cell phones, walkie-talkies, and cordless phones.
So your could paint the walls of your movie theatre so that those assholes who refuse to turn off their cell phones during the movie, and insist on actually ANSWERING and HOLDING A CONVERSATION right in the middle of a popular movie right in the middle of a crowded theatre before he gets his ass kicked, can't actually pull that move anymore because they won't get any signal. Unfortunately, that also means that you couldn't call out if you like, were trapped in a fire or if there was someone having a heart attack.
This paint, however, is bad news for another industry, and that is the tinfoil industry, because now all those crazies who used to line their walls with tinfoil to thwart the government radio signals that are coming in...they won't need tinfoil to protect themselves anymore. They will just be able to buy some of this paint and keep the tinfoil for their hats. If they feel that they need extra protection, just in case, they can certainly paint both the inside AND outside of their homes to take care of any wayward signals that just might make it through on accident.
The problem with the paint, however, is that unless they are able to tailor it to certain frequencies, theoretically it could keep people from having cell phone reception in their homes, which could be a problem in a society where more and more people are abandoning land lines. Maybe the phone company should jump on this bandwagon and pump some money into the research and manufacture of this stuff to try and make people have to get land lines again. That would be a smart move on their part.
I think that this paint will be very useful in certain situations, however, like the movie theatre example above. I also think that it will be very useful in apartment buildings: it could be used on the walls and ceilings between apartments, so the dipshit that lives below you can't glom off of your wireless signal. It would also work very well for businesses that are in strip malls or large office blocks, in order to allow them to keep their secrets, secret, which is always good.
Now, I am sure that this paint is expensive as hell, and it will be some time before it is fine tuned and as effective as they would like it to be, but it is an idea whose time had come, and that had definite potential. So get out your paintbrush and disable your passwords, it's time to redecorate and become a little more secure at the same time.