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Cyber-bullying: One teenager's experience

18 November 2013 Last updated at 09:00 GMT

Just over a fifth of children have witnessed a classmate or friend bullied online, and only one in 10 parents thinks their child is safe online, research suggests.

But the study from McAfee and the Anti-Bullying Alliance says only a third of those affected by bullying told their parents about the issue.

Graham Satchell met one teenager who was cyber-bullied and now helps others overcome it.