Children and teens love them - these social networking sites where they chat and swap (probably horror parent stories) with one another. And exchange photos and videos too. But sites like Friendster, MySpace, FaceBook and Microsoft's Live Spaces, are also where cyber-predators lurk.

You don't have too look too far from home for the social abuse.

Earlier this year, a 24-year-old undergraduate hungry for female companionship found pictures of girls from their social networking sites, and digitally attached their faces to naked bodies. This pervy perpetrator then tried to use these doctored photos to extort real nude photos from the girls.

In the US, concern over such sites has reached fever pitch following reports of paedophiles and other cyber-offenders scouring these sites for victims, culminating in the Deleting Online Predators Act.

The Act, designed to shield minors from cyber-predators, was passed last July by an overwhelming 415 to 15 vote, with US Congressman Michael Fitzpatrick, who introduced it, slamming social networking sites as a 'happy hunting ground for child predators'.

Needless to say, caution is necessary.

Women and children especially, must watch what they put online, said Microsoft's online services group regional product manager Barrie Ooi. Microsoft's Live Spaces has about 370,000 'active users' here.

His advice is to limit site access to only a few trusted contacts rather than putting up a public site. 'And don't leave any details that could lead back to your real identity,' he said.

Meanwhile, social networking firms - stung by criticism - have also been working hard to filter out the baddies. MySpace, with 67 million users began taking down sites of users under the age of 14 last year, and has since removed more than 250,000 such sites.

Meanwhile, Microsoft is working on a technology to prevent predators from downloading pictures of its users.

The scene is 'probably safer here than in the US...you don't hear of as many problems here', said Mr Ooi.

Even so, parents may wish to consider checking their children's social networking sites, just to be sure.

An attempted extortion

Song Yick Biau, 24, had been going online to steal women's passwords and their photos to harrass them for their nude pictures from December 2005 till he was arrested last January.

The then-Nanyang Technological University accounting undergraduate, hacked into at least nine women's instant messaging accounts. From their address books, he was able to identify more women. With these details, he trawled the Net to find out what these women looked like.

Song was able to find some of them on their personal websites, and downloaded their pictures. He then digitally stuck their faces onto naked bodies, and threatened to 'expose' them online - unless they gave him pictures of their breasts.

One of his victims made a police report, and Song was arrested and charged. He was sentenced to 27 months jail this January.