Violence is not needed if you have a talent for profanity and vicious sarcasm. Some idiot tries that with my gear will get an instantaneous very profane, very vicious, and very loud tongue lashing. Some asshat at the quarry made the very bad decision of touching my gear once. He learned very quickly he had made a very bad choice. Doubt he touches anyone else’s gear again.
One dive buddy was taught to turn his valve back a quarter turn. Stupid. I told him his business if he does that on his tanks, but if he dares to ever do that on my tanks, I will never dive with him again. So he doesn’t do it.