Have a Nice Day!
I came out of the mall one day to find that someone had hit my car. I asked a passerby what happened, and they told me that the guy who hit my car got out, looked at the damage, and quickly parked at the other end of the lot. So I came up with an ingenious plan for revenge. I went to where the car was parked, paint matched it to confirm that it was the one that hit mine, then I flattened all four tires, and left a note on their windshield telling them to have a nice day.
Story credit: Reddit / choppers_19