In two studies, the authors tested predictions derived from the social identity model of deindividuation effects (SIDE) concerning the potential of computer-mediated communication (CMC) to serve as a means to resist powerful out-groups. Earlier research using the SIDE model indicates that the anonymity of virtual groups can accentuate the power differentials associated with salient social identities: a cognitive effect. The present research builds on the strategic component of the SIDE model to show that CMC can also provide a channel of social support fostering resistance. In Study 1, students were more likely to express opinions normative for their group but punishable by the out-group (faculty) when CMC was available, independent of mutual anonymity. In Study 2, the authors directly manipulated the proposed mediator, social support within CMC, and showed increased willingness to express normative attitudes against out-group interests as a function of support. These studies reveal the importance of CMC as a medium for communicating and coordinating the social support central to collective action.