No matter how nice we are, some people are just plain rude. From selfish seat-takers to unreasonably angry customers, no one deserves a surly person’s wrath—and when we stand up for ourselves, the results can be brilliant. Here, Redditors share the best times they ruined a jerk’s day. 1. Backed Into a CornerI watched a lazy shopper park their grocery cart right behind another person’s car instead of putting it in the cart return. I got out of my car, moved the cart, and put it behind the lazy shopper’s own car. I then ran off and watched her have to get back out of her car since she couldn’t b…