The London riots, following on frequent Greek, French, and other European riots, would be immediately recognizable to even a Roman emperor. For decades, politicians have ridden a populist wave to office, fueled by promises of more free government stuff to favored constituencies. The mob serves whoever bids higher for its services, but always its expectations are that the each year's bid will be higher than the last. But eventually the money runs out, and the bids can't be increased, or even maintained. And the mob (or the army, or whatever group whose services are required to stay in power) then turns on those who thought they controlled it. And politicians have no one to blame but themselves, for they were the ones who trained the populace in the first place that their power in a democratic government should be used to extract goodies from the minority.