Since last more than forty years, social network analysis (SNA) techniques have evolved as one of the successful applications of Internet. Numerous reasons demand better understanding of the structure of social networks, need of their analysis and their impact on future Internet and society. For instance, finding the shared interest and trust could be one of the reasons to study social networks. Moreover, if in future, distributed online social networks are popular and bandwidth intensive, they can have a significant impact on Internet traffic, just as current peer-to-peer content distribution networks do. Regardless of one's stance on these phenomena, a better understanding of the structure of social networks is likely to improve our understanding of the opportunities, limitations and threats associated with these ideas. For instance, gigantic size of online social networks, their dynamic behavior, clustering and privacy policies held by users are some of the major challenges. This chapter presents an engraved review spanning from need of SNA to the implications associated with it.
