When I was at school being dangled out of second-floor windows and having large hardback text books thrown at my head was captured only by the evil eyes of the bullies and the fearful glances of the next potential victim.

Nowadays kids' embarrassment and sorry shame are caught on video and posted online to a worldwide audience of sadists and show-offs.

Now, sites such as YouTube, MSN and RateMyTeachers.com should be closed down to prevent the bullying of schoolchildren and staff online, teachers are demanding.

The annual conference of the Professional Association of Teachers (PAT) was told that victims of cyber-bullying are vulnerable 24 hours a day.

“Nowhere is safe from cyber-bullying. It can carry on 24/7 through mobile phones and in multiple forms online. Remarks, images posted online can easily be copied and made available to a global audience,” said Kirsti Paterson of the union’s Highland and Western Isles federation.

“In the short term, confronting this problem must be the closure of sites encouraging cyber-bullying,” she demanded.

A YouTube spokesperson said that it was a community site used by millions and the vast majority used it responsibly.

“Sadly, as with any form of communication, there is a tiny minority of people who try to break the rules. YouTube is part of the Government’s cyber-bullying task force, working closely with teachers’ unions and others. If teachers or anyone else see content that they think is inappropriate and breaks our guidelines then they can flag it and we will review it. If it does break our terms then we will remove it.”

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