Children use false identities to outfox parents monitoring them on-line.
Whatever the situation, social networking sites such as Facebook are a source of anxiety for parents, and a new study will only add to their alarm. Children are staying way ahead of attempts by parents and schools to police their online activity, the study suggests. And the latest ruse is a secret, fake-name Facebook account.
"Some kids will have two or even three," says Dr Barbie Clarke, of the youth research agency Family Kids and Youth, which conducted the research after monitoring online trends among a sample of schoolchildren in the UK.
"Their habits change and we're seeing them progress from the obvious lie about their age - allowing them to use Facebook in the first place - to this second or third identity. It's usually driven by mum picking up on something from their page and raising it with them. They want privacy and they want a secret world. A false identity can be used for nastiness, to anonymously bully, but generally it's about secrecy - like a secret diary, or dialogue they can have away from parents and other family members."
Many children use school facilities to access their fake accounts. "I have two," admits Harriet, 14.