getting aggressive under water?
About 30 years ago I saw a diver, perhaps in his mid 20's (like we all were) go on a "reef rampage". This young man went along a reef tearing off every sponge, coral, and anything else he could get his hands on. It was all in an aggresssive manner. The dive master idea was not yet common, and there was little to stop this nut. I considered pulling the cord on his BC, as they had CO2 cartridges then, to send him up. That might have made me the trouble maker.
Back on the boat I asked him what he was doing, and the guy sat there sullen and would not respond. I don't recall he did any of that on the second dive. This was back when Cancun was a new place, and the crew did no speak enough English for me to get my idea across.
Surprizingly, I was the only person on the boat that noticed, or cared enough to notice. I have never seen anything similar since.