Moves by MySpace to release data on known sex offenders using its site will only scratch the surface of the problem posed by predators using social networking sites, it was claimed today.

"Releasing the names of registered sex offenders is only a first step for MySpace in ensuring the safety of children on their site," said best-selling author R. Stephanie Good, who is working with the FBI to tackle child abuse on the internet.

"As someone who spends a lot of time communicating with sexual predators on the internet for the FBI, I have to stress that so much more needs to be done to adequately protect children on sites such as these.

"Without more safeguards, children will remain extremely vulnerable, especially to those predators who have yet to be caught.

"As for those registered sex offenders who have been identified on MySpace, I encourage attorneys general to actively pursue criminal charges."

Good began a collaboration in 2003 with FBI special agents from Squad C-20, which handles crimes against children, to track down sexual predators on the internet.