McAfee: Teens aged 14 and 15 are most at risk online
30 January 2014 Last updated at 15:51 GMT
Teenagers aged 14 and 15 are most likely to be at risk from harm on the internet, according to research.
McAfee and the Anti-Bullying Alliance found that a tenth of them have been approached by an adult stranger online and half had then sent the stranger inappropriate material.
Raj Samani, a cyber security expert at McAfee, says parents and teachers must improve their technical knowledge in order to monitor their children.
He told BBC Radio 5 live's Breakfast: "Yes education is important, but also having some degree of technical control... is very important as well."