Examined 21 cases in which crowds were present when a disturbed person threatened to jump off a building, bridge, or tower. Baiting or jeering occurred in 10 of the cases. Analysis of newspaper accounts of the episodes suggested several deindividuation factors that might contribute to the baiting phenomenon: membership in a large crowd, the cover of nighttime, and physical distance between crowd and victim (all factors associated with anonymity). The baiting phenomenon was also associated with warm temperatures and long duration of episode. These factors may be a basis for more systematic investigation.
Mann, L. (1981). The baiting crowd in episodes of threatened suicide. Journal of Personality and Social Psychology, 41(4), 703-709.