ABSTRACT
TheWeb has evolved from a simple tool for publishing text data, into a complex collaborative knowledge management system. This evolution is mainly due to the rapid spread of social computing services, such as blogs, wikis, social networks, social bookmarking, collaborative filtering, and recommendation and reputation systems. Social computing services are now starting to be used also at the enterprise level to communicate, share information, make decisions, and do business. This is in line with the emerging trend known as Enterprise 2.0, that is, the use of Web 2.0 technologies within the intranet, to allow for more spontaneous, knowledge-based collaborations. One of the main witnesses of this new trend is represented by online social networks, platforms that allow people to publish details about themselves and to connect to other members of the network through friendship or other kind of links. Recently, the popularity of online social networks is increasing significantly. For example, Facebook now claims to have more than two hundred and fifty million active users.∗ The existence of online social networks that include person-specific information creates both interesting opportunities and challenges. For example, social network data could be used for marketing products to the right
FIGURE 17.1: A portion of SellNet
customers. At the same time, security and privacy concerns can prevent such efforts in practice [3]. In this chapter we first introduce the main privacy issues in online social
network (Section 17.2). Then, we go into more details of the most interesting research proposals appeared so far to deal with these issues. Finally, we conclude with the discussion of other related research challenges in Section 17.6.
