In their research, Postmes and Spears wanted to discover whether being anonymous could make a person more or less violent or anti social than when he is identified. This was based on a previous assumption that stated that people tend to engage in more violent behaviour if they are anonymous.
However, their research revealed that anonimity, group size and reduced self awareness are not particularly linked to anti normative behaviour. Instead, they found that the difference lied in the importance of situation-specific norms, rather than general social norms.