PARENTS were warned today that on-line chatrooms were impossible to regulate - after an ex-US Marine was jailed for abducting a 12-year-old he met on the internet.

Toby Studabaker spent months "grooming" the girl on-line before flying from America to Manchester and taking her to France and Germany, triggering an international hunt.

Internet chiefs and child protection groups said there was no way the government could prevent the estimated 5 million youngsters who use the web coming into contact with paedophiles.

The warnings came as the M.E.N. discovered leading British chatrooms aimed specifically at children as young as 13 could be accessed without supplying so much as an e-mail address.

Studabaker, 32, was jailed for four and a half years at Manchester Crown Court yesterday after pleading guilty to abduction and inciting the girl to commit an act of gross indecency.

The court heard he had sent her a string of "cyber-sex" messages after meeting up on a virtual pet website used by 16 million people worldwide.

He flew to Britain last July and took the girl to Paris, Strasbourg and Stuttgart before they were traced from mobile phone signals and gave themselves up.

Studabaker faces a further three charges in America involving a child. He could leave Britain in months if he asks to serve his time in America or agrees to be extradited.

The judge, Mr Justice Levinson, said during sentencing: "Although the internet can be a force for very great good, it is not always so and its abuse can slip under the guard of parents who are not aware what their children can get involved in while on the web."

Det Chief Insp Mark Roberts, of Greater Manchester Police, said the case highlighted "the dangers of the internet and the need for tighter controls and monitoring".

A new law means anyone who contacts a child on the internet, leading to a meeting where the adult means to sexually abuse that child, could face ten years in prison.

But there is little to stop talking on-line - chatrooms are covered only by a code of best practice that recommends "alert buttons" and safety messages.

Some major sites aimed at teenagers have adult staff in main rooms, but visitors to the sites can simply enter a guest name to get access.

And any government laws would have no effect on chatrooms based in other countries.

Brian Ahearne, of the Internet Service Providers Association, said: "There are millions of chatrooms all over the world. The government could say it wanted all chatrooms to be moderated, but it doesn't govern the entire world."

A spokesman for internet safety group Childnet International said today: "The problem with regulation is that chatrooms are often in a part of the world beyond their administration. Someone can set up a chatroom and it will never be known to police because the internet is too big."

Research by the University of Central Lancashire found that 20 per cent of children aged 9-16 used chatrooms. One in 10 of those had agreed to meet someone they talked with on-line.

Net service firm MSN closed down its unmoderated UK chat rooms last October over concerns paedophiles were using them for grooming. And six of Britain's biggest mobile phone operators will censor content on their new 3G handsets to keep children away from gambling sites, pornography and unmonitored chatrooms.