People's health could be harmed by social networking sites because they reduce levels of face-to-face contact, an expert claims.
Dr Aric Sigman says websites such as Facebook set out to enrich social lives, but end up keeping people apart. A lack of "real" social networking, involving personal interaction, may have biological effects, he suggests.
http://news.bbc.co.uk/2/hi/uk_news/7898510.stm
