An empirical investigation on virtual communities shows how conflictive institutions influence the way members perceive their online interactions as being supportive or not of a more democratic debate. On the one hand community members identify their discussion lists as a space for free speech, emphasizing the relevance of having more access to information and channels for influencing society on issues related to environmental education. On the other hand they recognize obstacles for the free debate of ideas in these collectives, mainly to avoid conflicts with community leaders and members who are linked with powerful institutions. The research points out the relevance of considering the institutional environment to understand the nature of interactions in virtual communities in general, and their potential and limits as spaces for democratic debate in particular. Lessons from these informal online groups inform research on other virtual spaces, highlighting how the institutional environment influences these collectives.