Given the rise in new technologies which allow for anonymous interactions, understanding the effects of anonymity on the behaviour of individuals has become an important area for social psychologists to explore. While theories of deindividuation and dehumanisation propose that anonymity will automatically lead to aggressive and anti-social behaviour, the Social Identity Model of Deindividuation Effects (SIDE) argues that the social environment can mediate this effect. Divided into two phases, the first phase of this study was created to test the hypothesis of the SIDE model using a quasi-experimental design and the online computer gaming environment as a testing platform. The results of this phase, in which variables of competitive and cooperative group norms as well as gendered vocal cues were introduced, point to the salience of competitive environments in inducing aggressive behaviour. This effect may be heightened by large group sizes and human-player opponents. The second phase of the study involved further exploration of these results though open discussions held on various South African gaming-related forums. A number of important themes emerged from these dialogues, specifically that of aggression in others, personal investment, stress relief and gender. Ultimately, respondents to this phase concluded that the anonymity provided by the internet along with personal investment in the game’s outcome (such as in a truly competitive environment) were strong predictors of aggressive behaviour but that this could be mediated through strict administration in these environments. Overall, the results of both phases of this study offer support for the SIDE model and suggestions of new avenues for future researchers to explore.