I've never heard of that. Does it use the magnet to hold the door locked, or to unlock it? If the latter, what happens when power goes down or the battery runs out and you want to get in or out? If the former, what stops people from disrupting the power supply to bypass the lock?

The magnet opens the door. Its basicly home made, and its security through obscurity. Only some nabors and friends know about it, and about 4-5 people know how to unlock it(it doesn't use a key, it has a metal detector and a fake door bell, you put a bolt on the metal detector, which is hidden, and pres the fake door bell, and it opens, then open the door). You don't know it's there if you look at the outside of the door, you just see a standard lock. Its actually not that secure, anybody that knows how it workers can open it, we only use it if we are outh of town for more than a day, most of the time there is at least one person home. If the power goes down, you have to wait for it to come back. You can get in from a window if that happens and unlock it from the inside. It's not a problem from the inside, you just pull the lock. Ooops, i said too much :D