Social networking sites like Facebook could be monitored by the UK government under proposals to make them keep details of users' contacts.
The Home Office said it was needed to tackle crime gangs and terrorists who might use the sites, but said it would not keep the content of conversations.
It is part of a plan to store details of all phone calls, e-mails and websites visited on a central database.
Civil liberties campaigners have called the proposals a "snoopers' charter".
Tens of millions of people use sites like Facebook, Bebo and MySpace to chat with friends, but ministers say they have no interest in the content of discussions - just who people have been talking to.
Liberal Democrat MP Tom Brake said the websites contained sensitive personal details and he was concerned information could leak from any government-controlled database.Read more »