The worst problem is those that earn their keeping and also public welfare for inveterate non-earners have no right to defend themselves, and the state can`t/won`t defend them, either.

Scum comes in every colour/nation/orientation/whatever, but certain kinds of scum can hide behind its colour/whatever, and that`s another(?) problem.

Folks (various nations and various colours, mind you!) who pay taxes suffer loss and injury and sometimes get killed because of street riots, but they, except for those lucky enough to have get killed, still must pay (more and more) taxes to ensure the wellfare of the scum. One can be sued and convicted for a Politically Incorrect phrase, but one is free to break windows and burn cars and just shit the streets just because dealing with the one would be Politically Incorrect. As well as trying to make the scum earn their bread and drugs.

Know what? I suspect governments could deal with the scum of that kind, but they won`t. Because if loyal subjects see those can be forced to earn their living, the loyal subjects might get ideas about demanding that the gvt men and women really earn their own keeping, too...

You are talking about the UK riots ? 

Those, too.

Nassim Nicholas Taleb in his famous book "Black Swan" deals with the Nobel-prizes and reduces them to a level of mere yearly polemics often following popular trends (take the 2009 peace prize for President Obama for example with less than a year in the office) and also for many of the prize-winners of economics later being proven to have created plenty of negative developmental effects with their theories.