They don't have to be explained- the kids involved know exactly what they're doing, and know how it will be received, and no contrived "Im relly sory adn I haves lerned my lesson" posts are going to convince me they're interested in the events, so much as they are in the opportunity to be twits in front of a captive audience. They should have been booted immediately, and some should never have been let back in. It really is that simple. No one should have to be told to follow the rules, or not be an idiot.
My two cents anyway.