Nearly two in five (38 percent) nine to 12 year olds use social networking sites, says EU Kids Online.
According to the Social Networking, Age and Privacy report by the research project, 20 percent of the age group have a Facebook account despite the fact the social network has a minimum age limit of 13 years old.
Furthermore, a quarter of kids that have a social networking profile have their privacy set to 'public', which means it can be viewed by any other web user that's a member of the social network, and one in five admitted they list their address and or phone number - compared to just one in ten of those that set their profile to 'private'.
"It seems clear that children are moving to Facebook - this is now the most popular site in 17 of the 25 countries we surveyed. Many providers try to restrict their users to 13-year-olds and above but we can see that this is not effective," said Professor Sonia Livingstone from the London School of Economics and Political Science, the director of the project.
The research also revealed that 57 percent of children aged nine to 16 say Facebook is their sole or main social networking site, while one in six nine to 12 year olds and a third of 13 to 16 year olds have more than 100 online contacts.
Furthermore, 20 percent of nine to 12 years olds admit to communicating online with other web users they have no 'real-world' connection to.
"Since children often lie about their age to join 'forbidden' sites it would be more practical to identify younger users and to target them with easy-to-use protective measures. However we accept that abolishing age limits could lead to a substantial rise in the numbers using the site," added Elisabeth Staksrud from the University of Oslo, who helped compile the report.