The popular social networking web site MySpace has responded to growing fears about the security of its users by hiring a chief security officer for the first time.

Hemanshu Nigam, formerly the director of consumer security outreach and child-safe computing at Microsoft, has been hired to look at ways to stop paedophiles and other criminals from using the site to look for victims.

Nigam, who has already served as a federal prosecutor of internet exploitation cases, was an adviser to a congressional commission on online child safety and an adviser to the White House on cyberstalking.

“Hemu is a proven leader in online safety and security. We are fortunate to have him join MySpace, help us educate the public and protect our members’ safety and privacy,” said Chris DeWolfe, chief executive of MySpace.

In addition Rupert Murdock's News Corporation, which owns MySpace, is to run a major advertising campaign to warn against the dangers of online predators.

"One in five kids online is sexually solicited. Online predators know what they're doing. Do you?" read the advertisements, which are running on the MySpace site as well as on News Corporation's media outlets.

MySpace is in the top ten US web sites visited monthly and has over 60m users.