Hundreds of thousands of young people are being subjected to cyberbullying, with many being victimised for a year or more, new research suggests.
A study published on Tuesday reveals the long term impact of this abuse, with youngsters reluctant to go to school, living in fear of their safety and even resorting to self-harming or attempting suicide.
The Beatbullying survey of 4,605 children and young people in the UK, found that just over one in four (28%) 11-16-year-olds say they have been the victim of cyberbullying.
Cyberbullying is the bullying of another person through technology, such as mobile phones or the internet.
In more than a quarter of cases, the individual concerned was continuously targeted, suggesting that one in 13 secondary school children have faced persistent cyberbullying, the report claims.
The latest Virtual Violence II study says that with around 4.38 million secondary-aged children in the UK, it means that around 350,222 children have been the victim of persistent cyberbullying.
Of those that said they had been persistently cyberbullied, 23% said it last for a year or more, with 40% reporting the abuse lasting for weeks or months.
The study, which was commissioned by Nominet Trust and backed by the National Association of Head Teachers (NAHT), reveals that the effects of cyberbullying are far-reaching.
A fifth of victims said that fear of bullies made them reluctant to go to school, while 19% said their confidence and dropped and 14% said they did not feel safe.
In addition, five per cent said they had resorted to self-harming and three percent admitted they had attempted suicide.
And it is not just young people that have been the victims of cyberbullying.
The study, published to mark Safer Internet Day, found that one in 10 teachers say they have faced cyberbullying.
Almost half of the 339 teachers questioned (48%) said they have heard or witnessed colleagues being harassed.
Nine in 10 (91%) of the teachers surveyed said this bullying was an isolated incident that had arisen out of something that happened in school.
But the study also claims that cyberbullying has left some teachers afraid for their safety, or that of their family, while others said they felt emotionally and mentally violated, or that their teaching had suffered as a result.
Beatbullying chief executive Emma-Jane Cross said: "Cyberbullying continues to be a dangerous problem for a significant number of young people and we must not ignore its complex and often devastating effects.
"We as a society need to take responsibility for both preventing such harmful and anti-social behaviour, and dealing effectively with incidents of virtual violence when they occur.
"An integrated approach where we see Government, schools, parents, internet service providers and charities like Beatbullying all working together to keep our must vulnerable safe."
A second study of more than 1,300 teachers suggests that while the majority of school staff are confident that children are safe from internet harm at school, many are concerned that this is not the case at home.
Some 88% of the teachers questioned agreed or strongly agreed that their pupils know how to use the internet safely at school.
But only 58% thought that pupils had the skills and knowledge to use the internet safely at home.
The survey, commissioned by Vital, the Open University's Professional Development programme for teachers, also found that 91% of secondary school teachers and 52% of those working in primaries reported that their pupils have experienced cyberbullying.