Did you confront this child (who is obviously very young and looking for acceptance) and try to educate him on these matters? I suggest you do so.
If he rejects the help you are trying to give him, then he's an idiot and must be dealt with via drama or other means.
I'm sure if instead of jumping up and down screaming,"BLOODY MURDER," and we actually pm'd the kid, he would wise up to forum etiquette.