Children's charities have hailed as a "very positive step forward" the decision by computer giant Microsoft to close internet chatrooms to protect young people from predatory adults.
There have been several high-profile cases of internet 'grooming'
Chatrooms in Europe, Asia, the Middle East and Latin America shut down altogether while others will be continually monitored or available only through subscription.
The move follows several cases in which young girls have run away with men they met in chatrooms.
Chris Atkinson, internet safety expert at the NSPCC, said: "This announcement is a very positive step forward and will help close a major supply line for sex abusers who go to great lengths to gain access to innocent children by grooming them on the internet.
"For too long we have been told by the internet industry that chatrooms are global and that nothing could be done to stop their escalation and their use by adults who target children."
Microsoft will close its UK chat services, which currently attract around 1.2 million regular monthly users.
In the US, users will need to disclose their credit card details to subscribe, making them much easier to identify and trace. Chatrooms in other countries, including Australia, Japan and Canada, will remain free but will be constantly monitored.
CHATROOMS AND CHILDREN
One in five children aged nine to 16 regularly use chatrooms
More than half have engaged in sex chat
A quarter have received requests to meet face-to-face
One in 10 had met face-to-face
Source: Cyberspace Research Centre, July 2003
John Carr, an internet adviser to the charity NCH, also welcomed the decision.
"There has been a very substantial increase in sex abuse cases as a result of contacts made through chatrooms.
"The men who commit these crimes often target girls aged 13 to 14 and make out they are only two or three years older in order to win them over.
"They groom them over time and manipulate the child's emotions so they come to think of them as their best friend."