The point of a riot is to enjoy the license allowed by the anonymity of the crowd, but that conflicts with the modern young person's urge to photographically document every single moment of socializing and put it on his or her Permanent Record.
The world's best organized riots are in South Korea:
The rioters all get issued color-coded two meter cop-whacking sticks. And there are vast numbers of riot police in South Korea because they are conscripts. Unlike other countries, where the first priority of the riot police is to prevent a riot from breaking out and the second priority is to quell rioting, in South Korea the riot police are there to Do Battle. A good time, apparently, is had by all.