Anonymity doesn’t always produce anti-social behaviour, despite the Online Disinhibition Effect (aka GIFT theory). Here’s the pdf of a study by Kenneth Gergen, Mary Gergen and William Barton from October 1973 in Psychology Today that describes an altogether different kind of reaction when people are experimentally anonymised.
This was referenced by Johnson, R. D. & Dowling, L. H. (1979). Deindividuation and Valence of Cues: Effects on Prosocial and Antisocial Behavior. Journal of Personality and Social Psychology, Vol 37(9): 1532-1538, and was the inspiration behind their work that identified context as king in deindividuated situations.