Social networking sites such as Bebo are to be given the email addresses of known sex offenders so they can be banned.
The Home Office's UK Social Networking Guidance, issued last week, says police will hand over the information in a bid to monitor paedophiles online. Child abusers face up to five years in prison if they fail to provide a correct email address.
Jim Gamble, chief executive of the Child Exploitation Online Protection Agency, said: "This has the potential to accelerate online child protection and should provide the vital reassurance that protecting the vulnerable is being taken seriously."
The guidance also outlines plans for a Kitemark standard for software to prevent children seeing unsuitable material.
