"Beware of paedophiles on the prowl", is a warning issued to teenagers who are increasingly posting explicit images of themselves on the Internet.
A report by the Child Exploitation and Online Protection Centre (Ceop) highlights an increasing trend of risque images that young people have taken of themselves appearing on the web.
"Children are engaging in risky behaviour. They are putting up images on the Internet for their boyfriend or mates without thinking about the consequences," Sky News quoted Zoe Hilton, the head of safeguarding and child protection at CEOP, as saying.
"They are not thinking of their digital footprint. It could be looked at by future employers or swapped among sex offenders. The core message is children need to be educated," she added.
Hilton also claimed that some privacy settings on social network websites were "very confusing and not easily explained".
She said the rise was partly down to a greater awareness of the problem, more children using the web, young people increasingly posting explicit images of themselves online, and an increase in grooming.
Most incidents were reported through the ClickCEOP button, put on websites used by children, to make it easier to report problems.