I have Toyota Tunrda that I keep armed with an extended trailer hitch/ball on at all times. Many years ago, while on a crowded expressway, I had a guy in a newer sports car riding my tail so close that I thought he'd start pushing me. Because he was so close to me (and the ground), I knew he couldn't see the stopped traffic about 1/4 mile up the road. So, I deliberately waited slightly longer than I should have to apply the brakes - which resulted in a harder than normal stop than he was expecting. He compensated well, so I released my brakes a bit, getting even closer to the stopped traffic, and then I hit them again pretty hard. Not expecting a second hard stop, the guy overreacted and locked them up, nailing my hitch. The impact occurred at less than 20MPH.
The schadenfreude feeling was extreme. Especially when I saw the steam of his punctured radiator rising above my tailgate. I got out and inspected the damage. The guy got out of his car and said "Well, it looks like there's no damage to your truck". I agreed, and wished him well and left. He was stranded. Rather than accepting that I caused the accident, I prefer to look at it as performing a public service. I would hope that the a-hole will reconsider riding someone's ass in the future.
FWIW, I really had no damage to the hitch, receiver, or truck. A class III can do a lot of damage to smaller vehicles before transferring energy to the host vehicle.