Rory Cellan-Jones looks at the social networking sites of the future and asks where the phenomenon is heading. New sites are springing up all the time. The future of social networking could lie in localised sites geared towards specific interests, in limiting your online circle to your closest friends, or in sites that allow users to keep control of their personal information. Finally, Rory returns to the social networking pioneers of the 70s and 80s. How do the hippies and hackers who created the first social networks think their revolution has turned out? Part 3 of 3.