Telecom regulator Ofcom has published a guide for parents that explains how to use parental controls on mobile phones and how to report inappropriate content. It comes as the regulator publishes a survey suggesting that less than 10% of children aged 7-16 use a mobile phone to go online. Although 44% of children with mobiles have a device that's capable of browsing the internet, only 12% of them actually uses the mobile phone to go online - and with almost three-quarters of youngsters having a mobile, that's just 9% of all children in the UK.