"It is not crucial, in the generative stage of a riot, that the participants act literally simultaneously. What is crucial is that offenses occur rapidly enough to overwhelm the police. From the rioter’s viewpoint, there is safety in numbers. There comes a point at which the police pass from inadequacy to impotence."
David D. Haddock and Daniel D. Poisby, UNDERSTANDING RIOTS, Cato Journal, Vol. 14, No. 1 (Spring/Summer) 1994