THEY'RE billed as kid-friendly social networks that are safe for all ages.
But it didn't take long to find disturbing and inappropriate messages splashed across them.
In a few hours surfing Moshi Monsters, dubbed "Facebook for kids", The Sunday Mail found users engaged in sexual role-play, swearing and posting their contact details publicly on the system.
While Facebook restricts access to children, social networking sites aimed at kids such as Moshi Monsters, Neopets and others have filled the gap, amassing hundreds of millions of users combined.
But while such sites emphasise safety and have filtering systems and moderation in place, The Sunday Mail found disturbing messages, including sexual role-play, on the networks. Parents and experts have raised concerns predators could be circumventing their safety measures.
Bravehearts founder Hetty Johnston said pedophiles could use the games to "groom" their victims and lure them into relationships and real-world meetings, with potentially disastrous consequences.
"They're just not safe places for children," she said.
Ms Johnston said her organisation had counselled clients who had been exposed to inappropriate material aimed at underage kids.
She said one 15-year-old girl was raped by two men after a 42-year-old man posed as a teenage boy on a different site.
The man lured the girl into a relationship and when she eventually sneaked out to meet him, she was raped by the man and an accomplice.
In 2003, a 31-year-old US pedophile abducted a 12-year-old girl he had groomed over Neopets, took her to Europe and had sex with her.
In the UK, police have recently sent officers to more than 300 schools to raise awareness about online predators who may use social games to target victims.
Detective Senior Sergeant Wayne Steinhardt, an operations leader with Task Force Argos, confirmed to The Sunday Mail that predators could use children's social networking sites to groom unsuspecting children.
"Those dangers are always out there and we're aware of those dangers," he said.
But he said the risks could be managed if parents educated their children about the dangers and maintained open communication with them.
"I think you can use the internet safely as long as you adopt a number of protective strategies," he said.
Sen Sgt Steinhardt said Task Force Argos had an "active presence" online to help protect children.
"Task Force Argos expends considerable effort to protect children online and we employ a variety of contemporary technology to effectively target online predators," he said.
"Rest assured police will always respond to all unlawful online activity directed towards children."
Rebecca Newton, chief community and safety officer for the developers of Moshi Monsters, said the company used cutting-edge technology to filter messages and flag inappropriate behaviour.
She said while the website had 60 people dealing with safety and community moderation, there was a four-hour space each day where no monitoring took place.
"We don't have any real-time chat, so nothing truly dangerous can happen in four hours," she said.
Ms Newton said she wasn't aware of any instances where a predator had used the site to contact a child, and said the company worked closely with law enforcement around the world to ensure the safety of their users.
"If we see anything we think is a little bit odd or strange we contact the authorities," she said. "Generally, we've found that in almost all the cases where there's misbehaviour, they know each other from offline."
Neopets did not respond to requests for comment.
Children at risk from predators in devil's playground online | The Courier-Mail