Ministers want every child to have their own e-mail address and access to the Internet. But yesterday teachers called for more protection against children down-loading pornography, and appealed for tough regulation of Web companies.
Michael Moore, head of information technology at Little Hulton community school in Manchester, said sixth-formers at one school in the North-west had been targeted by paedophiles soon after the introduction of e-mail.
He said: "A paedophile ring in Sheffield discovered the system and invited students to take part. They suggested friendships with other males. When schools get involved in the Internet they seek publicity because it's good for the school and people with the wrong intentions certainly can easily identify students at the school and use e-mail.
"The students reported it very quickly and the school reported it to the police.
"It's easy to send e-mail to a block of people, and it's very low cost. Unless the teachers themselves read every entry it's very difficult to monitor it."
The Association of Teachers and Lecturers' meeting in Bournemouth called for schools to be given electronic guards against unsuitable material, to protect teachers from legal and other challenges from parents.
They said obscene or racist material was available on the Internet even if computers were screened using so-called "firewall" software. Teachers fear they could be held liable if schoolchildren download illegal obscene material.
Mr Moore said in another case a music teacher had found pornographic pictures after searching the World Wide Web for the score of the The Sound of Music. He said: "When they are on the Internet, students will try looking for this material and they will want to amaze their friends."
Brian Waggett, a teacher at Range High School in Formby, Merseyside, said: "Pupils will be attempting to access the Net and they will find dubious material. They will find it and you must be on your guard. Nobody can police the Internet completely, it's a monster."
Terry Gallagher, a teacher at Top Valley School, Nottinghamshire, said: "Children are naturally inquisitive ... 27 per cent of families have Net access. When they are not on a school provider, these young people will be able to access all these sites and I feel our Net education at school should acknowledge they exist."
Stephen Byers, the school standards minister, said British Internet providers were trying to police their services, but unregulated foreign sites were easily accessed. "Guidance has already been given to teachers. But it's extremely difficult."