The paper presents a discussion on different ways of interaction and collaboration among users of Web applications oriented to learning. We discuss whether the "social" applications, such as Facebook or MySpace, follow a truly "collaborative" approach, very common after of the advent of Web 2.0, or a more simply "participatory" one. We argue that virtual communities, if specifically adapted to life-long learning settings and not generalized to social networks, are more suitable for educational purposes, thus allowing a better use of social network tools like blogs, wikis etc.