BBC Radio 4's Analysis: With Friends Like These will be broadcast on Thursday, 8 November 2007 at 20:30 and repeated on Sunday 11 November at 21.30 GMT
Are we revealing too much information about ourselves?
The Internet is now the centre of many peoples' lives.
It's a place where they work, play, and socialise.
Many of the internet's most popular sites are claiming more and more of our time.
Social Networks are especially popular with the young, for whom membership of Facebook or MySpace is almost mandatory.
But for these sites to work, they require the users to reveal large amounts of information about themselves, and their friends.
And for the first time ever, our youthful indiscretions, our interests, and our thoughts, are public and searchable, and will be around, perhaps, for ever.
But this doesn't seem to put people off from using social networking sites.
On the contrary.
Facebook in particular is attracting an ever-increasing crowd including many 'older' users in their 30s and and 40s and it has become so popular that many employers have decided to ban their workforce from using it in the office.
Ben Hammersley asks whether social networking sites have changed our notion of privacy and if so, what the consequences for society might be.
In 'With Friends Like These', Professor Robin Mansell of the London School of Economics discusses how different generations each see the concept of personal privacy, while danah boyd from the Berkman Centre for the Internet and Society at Harvard says that online identities are now a fundamental part of growing up.
Adam Joinson of the University of Bath explains the psychology behind online relationships while Will Reader from Sheffield Hallam University, has new research about the strength and nature of these relationships - just how much of a friend is an online friend?
And David Evans, from the Information Commissioner's Office says that the government's privacy watchdog is so concerned about the information people give away about themselves, that the Information Commissioner is about to issue guidelines for users of social networking sites.
Presenter: Ben Hammersley
Producer: Ingrid Hassler
Editor: Hugh Levinson