My friends were talking about these things you can get for your hard disks that you must have a key in the right slot when you turn it on, or else the hard drive will self format. This is to use when your house is raided for whatever reason i guess, so when they boot up your comp for info, u make sure u grab the key beofre they do, so they cant get anything. A company also made these things out of thermite that melts the hd completely when not turned on the correct way.