Most of my pc exploits involved searching for days to find just the right place to set 1 equal to 1, doing it and declaring victory.<p>I spent a <i>huge</i> amount of time on my Amiga tweaking disk copy algos to foil those rotten floppies that had tiny holes physically burned or punched into the medium. After you got the damn thing to copy, then you had to hunt through the executable to find out what behavior the program expected from the disk drive when it encountered the hole and put in a jump to skip this.<p>I remember my 13 year old self exclaiming "they use the drive error <i>as the key</i>?! That's just diabolical!"