I suppose I should wait until I hear more about it, but from the various internet reports I've seen, it sounds like the dudes with the sound system were acting in a seriously fuckwitted way. I'm not defending anything the police did, but allowing such predictable, pointless and counter-productive situations to arise is a problem. I mean bringing a sound system into a pub is a certain way to percipitate a pointless confrontation with the filth. It's obnoxious, anti-social and more than anything else, it's fucking stupid and irresponsible. If you're going to do such things which fuck things up for everybody else, you should be told where to go in no uncertain terms.