A new book on cyberbullying suggests teachers are partly to blame for the problem and should try harder to understand why pupils put hateful comments online.
Shaheen Shariff, an assistant professor at McGill University in Canada, has been studying cases of computer and mobile phone-related bullying worldwide.
Dr Shariff took a personal interest in the subject after her daughter, then aged 15, was the subject of a threatening email from classmates. The culprits went unpunished.
In Cyberbullying: battle or opportunity?, published today, Dr Shariff says she can provide no simple tick-box solutions for schools.
Instead of suspending pupils who are caught, or crudely blocking access to technology or websites, she urges schools to understand what has led to the bullying. She is critical of those, like the Professional Association of Teachers (PAT) in Britain, who have called for banning websites such as YouTube,
Hurtful comments made by pupils about their teachers on websites could also contain some truth, she said. "In some cases where teachers have been cyber-libelled on Facebook or MySpace, there may be underlying frustrations on the part of the student that have not been addressed by the teacher.
"Although there is no question that students' statements that accuse their teachers of being paedophiles or nymphomaniacs can significantly affect a teacher's reputation, statements about the possibility of teachers' disrespectful attitudes towards students should make teachers reflect on their own behaviour and consider ways in which they might adjust their teaching approaches."
Dr Shariff cites the case of Bram Koch, a 14-year-old pupil from Ontario banned from a school trip after writing lewd comments about a teacher on a Facebook page.
He had not realised that the comment might be seen by the teacher, she said, because pupils regarded the internet as private space.
"If I were (his) teacher, I would have students research the etymology of bullying, its history and school censorship controversies involving freedom of expression and supervision - and ask them to come to decisions about where the line crossed over to become cyber-libel and criminal expression".
Dr Shariff recommends better training for teachers in technology and the law, and getting them to help pupils set up websites and discussion pages, so young people regard them less as a private space.
Philip Parkin, general secretary of the PAT, said he welcomed extra training for teachers and classes on the ethics surrounding websites.
But he said that insults levelled against teachers should never be considered an acceptable form of comment on their work.
"A pupil with a dislike of an individual teacher can simply make unfounded accusations," he said. "Is a decapitated image accompanied by a death threat really an acceptable way of 'expressing underlying frustrations'? Responsible feedback from students is one thing. Malicious persecution is another."