That's nothing. Back in the ye old DOS era, AutoCAD and other high-profile companies had a special system for copy protection: Since everything was on floppies, they would put a bad sector on the floppy at the factory that the program would look for. Then, the program would get data from that specific spot; if it was corrupt, it was a real copy. Obviously, it is impossible for someone to figure out where to put a corrupt sector on the disk.