Network communities as well as social networks sites are special cases of online social interactive environments. According to Rheingold (1993), who chose the term "community" (Gemeinschaft) to denote the early experiences of online aggregation, De Cindio and Peraboni (2010) suggest to name Gemeinschaft the free interactions among people; while the term Gesellschaft denotes the corpus of rules that govern the online life, i.e., the normative aspects typical of a society. Network communities differ from social networks sites in the sense that "Social Networks Sites are primarily organized around people, not interests" (Boyd and Ellison 2007), while network community/ies members more explicitly recognize a common interest that holds people together for sharing knowledge and experiences (DeCindio and Ripamonti 2010) and goals (Preece 2000). Moreover, the rules of behavior of the Gesellschaft dimension of any online social interactive environment in network communities identify more explicitly a social structure, as (De Cindio et al. 2003) shown in the case of the Milan Community Network.