From Joshua Clover’s Riot. Strike. Riot pg 2. He argues that the return of the riot reverses a long term trend observed by Charles Tilley, in which the riot had given way to the strike as the foremost tactic in socially available repertoires of contention:
As the overdeveloped nations have entered into sustained, if uneven, crisis, the riot has returned as the leading tactic in the repertoire of collective action. This is true both in the popular imaginary and the realm of data (insofar as such matters give of statistical comparison). Regardless of perspective, riots have achieved an intransigent social centrality. Labor struggles have in the main been diminished to ragged defensive actions, while the riot features increasingly as the central figure of political antagonism, a specter leaping from insurrectionary debates to anxious governmental studies to glossy magazine covers.
Mark Carrigan 