Anyone who has worked in the service industry knows how rude, demanding and offensive some customers can be. While any upstanding and self-respecting server knows not to mess with someone's food, we do have other ways of getting back at you. Sure, these revenge stories may be petty, but the payoff is so, so sweet. Remember: Servers are human beings, not your slaves. Hopefully you'll keep these tales in mind the next time you stiff your waitress or bartender.
If these stories don't teach you a lesson in kindness and politeness, then there is no hope for you, and you should just eat at home.