One in five young people has been a victim of cyber-bullying, which experts warn can cause more psychological damage than traditional bullying.
Hate emails, threatening texts and humiliating images posted on social networking sites are twice as likely to be targeted at girls rather than boys, according to research by Anglia Ruskin University (ARU).
Cyber-victims can suffer more because they feel unable to escape from online and mobile phone threats. The hidden identities of cyber-bullies as well as the ability for messages and images to "go viral" within minutes, amplifies the threat, said Steve Walker, the study's co-author and principle lecturer in child and adolescent mental health at ARU.
The ARU survey of nearly 500 10- to 19-year-olds found that half of those bullied said their mental health had suffered as a result. More than a quarter had missed classes and more than a third stopped socialising outside school.
The online survey was followed by two focus groups which analysed in more depth the experiences and fears of 17 youngsters in London and Leeds.