The software giant Microsoft declared war on internet paedophiles last night by announcing the closure of its thousands of UK-based chatrooms used by millions of people.
It will also restrict access to chatroom systems around the world, allowing only identifiable, adults living in the same country to use them.
The decision is a significant precedent, the first time one of the biggest internet service providers has cut off an element of the World Wide Web in reaction to concerns over misuse.
The Government is so concerned by the dangers of chatrooms that it is drafting legislation, expected to come into force in the autumn, that will criminalise "internet grooming" by creating a new offence for any adult to arrange to meet a child under 16 with intent to abuse them sexually. It would carry a sentence of up to five years in jail.
The move by MSN, which has a total of 350 million visitors worldwide to its online service every month, was welcomed by charities including NCH and NSPCC, the children's protection charity. The NSPCC called on other internet chat providers such as Yahoo!, which still operates online chatrooms open to anyone, to follow suit and shut them.
But Rachel O'Connell of Lancaster University, a specialist in online behaviour, warned that closing down chatrooms wholesale would only encourage children to go to other less- monitored parts of the Net - where they would be followed by paedophiles. "If you're going to do this sort of thing you have to consider the logical conclusions of it," she said.
Since the internet became widely used in 1995, its functions have expanded rapidly, leading to a number of worries about potential abuse. Previously, service providers had resisted calls to close down functions that could have harmful effects on users, arguing that they brought benefits too.
Chatrooms allow people to converse through text online in real time. Because there is no rigorous way of confirming identity online, they have become notorious for paedophiles posing as teenagers, using them to pick up children and "groom" them for sexual abuse. In May, a Cambridge man, Michael Wheeler, 36, was jailed for three years after using an MSN chatroom to befriend a 12-year-old girl and have sex with her. In August last year, James Gilmour, 50, a convicted rapist who was out of prison on licence, tried to trick an 11-year-old girl into meeting him after chatting online with her.
Dozens of similar cases have been reported, leading the Home Office to set up a taskforce with charities and internet providers, including MSN, to consider how to tackle it. The Independent understands that one of the proposals for guaranteeing online identity is to require users who want to take part in online discussions to upload a picture of themselves, which would have to be verified by a teacher or policeman.
MSN said that the announcement, which will see all its UK chat services, presently used by 1.2 million people each month, shut down on 14 October, is part of a "global decision" by the internet provider run by Microsoft. Gillian Kent, director of MSN UK, said: "We felt it necessary to make these changes because online chat services are increasingly being misused." The cost of closure will run to millions of pounds in lost advertising. In the US, only people able to give a credit card number will be able to access the chatroom service.
John Carr, director of the children and technology unit at the children's charity NCH, was delighted. "This is a momentous announcement," he said. "Here we have the world's leading internet service acknowledging open, free, unmoderated chat cannot be made completely safe for consumers and children ... I think every other chat provider in the UK is going to have to reflect on how, or indeed whether, they continue their own open access chat services."
Dr O'Connell, who has been investigating paedophiles and the internet since 1996, said: "The children and teenagers on these chatrooms have all built their own private communities and to try to keep those going they'll start giving each other their personal e-mails and mobile numbers and even addresses. Parents will have to talk to their kids to tell them not to do this. But all that's really going to happen is that they will move on to other, unmoderated sites, or to other technologies like instant messaging." AOL, MSN and Yahoo! all offer instant messaging, which allows pairs of people to chat online; there are more users of that than of chatrooms.
Dr O'Connell said killing off chatrooms would not wipe out paedophilia online. "We now have an online community with the ideology that says sexual contact with children is OK. The trouble is that with each thing you do, they will come up with strategies to get around it."