More than a third of young people have been affected by cyberbullying, but many do not tell anyone, research suggests.
The new study also reveals fears among youngsters that cyberbullying - the bullying of another person through technology - will continue to rise.
Research commissioned by the Diana Award children's organisation found that 38% of young people had been victims of, or knew someone who had been a victim of, cyberbullying. Of these, 39% said they had experienced cyberbullying once or twice.
Maggie Turner, chief executive of the Diana Award, said the report - based on surveys of 1,512 children aged 12 to 16 across England - shows that more needs to be done to protect young people.
The findings show that of those who have seen or experienced cyberbullying, more than one in four (28%) had never told anyone about it and more than half (53%) did not save any evidence of cyberbullying.
The study, carried out to mark Anti-bullying Week which runs from November 14-18, also looked at the types of cyberbullying experienced by young people, and reveals concerns that the problem is increasing.
One in four (26%) of those affected by cyberbullying said this had been in the form of abusive emails, making it the most commonly used method. This was followed by abusive texts (24%) and prank and silent phone calls (19%). Asked whether cyberbullying is increasing or decreasing, the majority, 78% in total, said they thought it was on the rise.
However the problem seems to be more common outside the school gates. Half of those questioned felt that cyberbullying occurred outside school, rather than inside, with a similar proportion (56%) saying it is experienced at home.
Ms Turner said: "This report clearly identifies the shocking and increasing numbers of young people affected by cyber-bullying. These findings plainly evidence that funding and improved safeguards are still needed to better protect our children in society."
The study showed that the highest proportion of those reporting cyberbullying told a friend or peer mentor (28%), she added. "Therefore proving that peer-led programmes, such as the Diana Award Anti-Bullying Ambassadors Programme, would provide the most appropriate vehicle of preventing and supporting young victims of bullying."