Not sure what you are getting at. If the sign annoys you, then don't camp there. If it is showing what yobs are doing, and what others have to do to counter them, then fair enough.
Last time went in for a drink at Dargo we were talking to the pub owner and he was telling us some of the things he has to put up with. I couldn't believe that people behaved so badly in a popular camping area. As far as I was concerned they are all fair rules, and the owner is big enough to make his point known.
I must admit, as time goes by I despair more and more at the stupidity of some four wheel drivers, but then again I getting to be a very grumpy old man.