Well, that was sooner that I predicted : Conservative Government -> cuts to spending affecting the poor the most -> rioting in the streets.
When William Hague described the current Tory party as "Children of Thatcher" I didn't think we would try and replicate it all, right down to the rioting.
Essentially, what started as a social flash-point was taken advantage of by violent elements; the sudden appearance of Molotov cocktails suggests to me that some people were planning to get violent, plus reports from local residents that they didn't actually recognise a lot of the people rioting because they weren't local suggests an organised element.
Once the rioting starts, the disaffected poor in the area see it as a way of expressing their anger at the current state of things so it continues for several nights and spreads to other poor areas where people feel otherwise powerless. The looting is opportunistic theft by individuals who are either desperate or immoral (on an individual basis).
@W3bbo: It's not 'social decay'; I don't imagine you remember much about the riots in the 1980s, but try and remember that this has all happened before. It's about a section of society who know that the current government doesn't give a flying f**k about them and showing their displeasure in the only way that they know will make the news headlines. As disgusted as I am at their actions, I think it's worth trying to understand why it's happening here and now and not just put it down to "chavs".
Oh, and owning a Blackberry is not an indicator of individual wealth; it's like saying that the poorer elements of society can't afford Sky TV or cigarettes..