What's happening in London can be attributed to unemployment and social unrest surrounding global recession, but it can also be attributed to ideas fed to young people for decades. Eventually, ideas find their way into social action, and the constant class warfare ideas have finally manifested themselves in destruction and looting. The irony is that these young people are looting items associated with materialism.
They've been taught to hate the reach, yet they want what the rich can buy, so they take it. The ideas of "social justice" have given them justification for righting the wrongs done to them by the upper class. Rather than teach young people how to work to make a better world in which government's and corporations don't collude to keep competition at bay, the authorities have justified State power as a means to take what is owed to the lower class from the upper class. These young people are merely doing directly what government has been doing indirectly for a long time -- looting the rich and buying support of the middle class and poor. It's quicker and more efficient to just break the glass and take what you want.