http://www.msu.edu/user/trescami/thesis.htm
A user?s perceived anonymity is the ability to remain unaccountable within his or her social environment for actions and dialogue, both legally and socially. A user?s personal views are influenced by lack of visual appearance, the flexibility of a label that is different from the user?s normal persona, and relative protection from physical and social repercussions. Users may often perceive that they are anonymous when they are not, may find a deeply personal attachment to a label so that it becomes part of their own personality, or may be far less protected from repercussions than they perceive.
A long read, but a good read. It offers a little insight into why people are retarded on the internet.