There are a few simple rules in Retail: The customer is always right, even when they're wrong.Insults, threats, harassment and physical violence are accepted. Hell, those things are expected.Smile. No matter what happens, you need to get paid.This is how it's always been, and how it always will be...Until today. Enough is enough. It's time to get even, one nasty customer at a time. Once you get past the sticky issue of morality, revenge is easy. No one really sees the cashier or the stock person at the grocery store. We're irrelevant and forgettable.It's amazing what you can get away with when you're invisible.