riot
n. violent disorder involving a large, hostile, and typically disorganized mob. A number of different conditions can lead a crowd to riot, including panic over a limited resource, contagion of affect and violence in provocative situations, confrontation with another group, and oppressive social conditions. Although the concept of group mind traditionally has been associated with riots, emergent-norm theory suggests that rioting individuals are conforming to emergent-situation norms, and social identity theory suggests that riots are instances of intergroup conflict. See also collective behavior.