One in four teens in the UK may be putting themselves at risk from paedophiles by posting their personal details on social networking websites such as Facebook and MySpace.
The risk comes to light in a new BBC programme that is due to be shown in the UK.
In it, a businessman named simply as Peter, admits that he had surfed the web looking for young girls online.
He is also urging parents to take PC's out of kids' bedrooms by revealing that sex perverts are taking advantage of webcams that let them see the people they are chatting with.
As a part of the programme, researchers posted a bogus virtual identity of a 14-year-old girl called "Jane Brown" on three popular sites. They described her as a typical teen who likes music, dancing and is hoping to make new friends her own age.
The researchers noted that within just 20 days, "Jane" had been flooded with pictures of male genitalia and asked highly intimate questions, such as whether she was a virgin and if she would have sex.
They have now passed these notes to the police for further investigation.
Det Sgt Nick Duffield, of the Metropolitan Police Paedophile Unit, said that the programme showed the need to maintain caution.
"What we are saying to teenagers using these sites is no names, no school names, mobiles or any other personal information," the Telegraph quoted him, as saying.
Research for the documentary also found that 25 per cent of 11- to 16-year-olds had posted details such as their mobile phone numbers or full names on these sites, and that 15 pct regularly chatted with strangers.
A poll of more than 400 teens also showed found that parents for the most part remain unaware that their kids are revealing their personal details, and that according to the figures of the poll, just 13 per cent of the 450 parents questioned what their kids were up to.