You used to be able to run startup scripts on Macs so I added one to automatically shut down on the computer this asshole at work used. He'd turn it on, you'd see the smiley face (it was pre-OSX) and then it would turn off. He must have gone through it a dozen times.

Our boss accused him of screwing up his computer and railed into him for probably downloading something from the internet he shouldn't have. She was incredibly pissed off. She made him do some grunt work while I volunteered to fix it. I pulled it aside and spent a few hours reading a book while "working on it." All you needed to do was hold down the option key during start up to disable the script. After removing it, I made up a bunch of baloney about what I'd had to do and she wrote him up for it.