The nature and depth of technological interference on social activities online are not fully understood. We discuss one such type of interference-compulsory institutionalization, the process by which noninstitutionalized face-to-face informal groups, who typically adopt implicit norms tacitly accepted by members, must create a set of explicit group structuring rules with very specific computer-encoded meanings and abide by them when they migrate to online group environments. In societies where rules can be bypassed in view of more highly valued social norms, like the Brazilian society, compulsory institutionalization may undermine experiences that are highly valued to face-to-face groups. In this article, we contrast the findings of our study with a Brazilian group of potential groupware users and those of our semiotic inspection of YahooGroups, SmartGroups and MSN Groups. We show how the systems may frustrate the group's expectations and limit their interaction online. Reflecting on the causes and consequences of compulsory institutionalization, we conclude that the social-technical gap in group technologies may not be possible to bridge completely, and that the fulcrum of scientific research in this area may include some new aspects. q