The term riot refers to large-scale, usually violent, mob behavior. A panic is a crowd whose members feel threatened by danger or the loss of scarce resources. Fads, crazes, and fashions. A fad is an abrupt, short-lived change in the opinions, behaviors, or lifestyles of a large number of widely dispersed individuals, which disappears without leaving a lasting impact on society. A craze is essentially the same as a fad, but more widespread, expensive, or irrational.
Fashions simply refer to fads in clothing style or manners.
Rumors and mass hysteria. A rumor is false information conveyed about a given situation, serving to reduce anxiety by providing reassuring reinterpretations of ambiguous or chaotic events. Mass hysteria is the spontaneous outbreak of atypical thoughts, feelings, or actions in a group or social collective, including psychogenic illness, common hallucinations, and bizarre actions. Rumors play an integral part in a variety of collective phenomena, including riots, panics, and crazes. Prospective rioters, for example, often mill about for hours swapping stories about injustices before commencing mass action.