Illegal though it may be, child pornography and its virtual variants remain relatively common online. Responding to Harper's blog entry, someone posting under the name ColeMarie Soleil claimed, "There is TONS of child-to-adult sex going on in Second Life."

Not everyone sees that as a problem. Some Second Life residents who commented on Harper's blog post criticized Linden Labs for banning role-playing between consenting adults. Others pointed out that virtual killings occur frequently in Second Life and in games like World of Warcraft and that no one gets arrested for murder.

One difference, however, is that explicit images of virtual children often indicate the presence of explicit images of real children. In the Second Life case, for instance, the allegations involve both rendered and actual images of children.

Chris Peterson, a writer for the satirical Web site SomethingAwful.com, said he's visited ageplay areas in Second Life and was revolted by what he saw: "These were avatars of prepubescent children screaming in baby talk, 'Stop torturing me,' while individuals are doing unimaginable thing. They're creating childish avatars that are four or five year old, and the sex acts are in a room covered with children's wallpaper," he said.

Other Second Life residents expressed skepticism about what they see as a face-saving move by Linden Labs. "Dozens of times in the last, LL employees themselves have come out on the community forums and publicly defended age-play as fantasy role-play between consenting adults," said someone posting under the name Charlotte Wirtanen. "Now suddenly everyone is pretending that they had no idea any of this was happening, when age-players are a massive, massive part of the SL user base."

Aftab believes that incidents like this may prompt social networks to adopt social policing though better reporting policies and procedures. She said that she's currently working with teen-oriented social site Xanga on better community reporting tools.

The neighborhood watch is coming soon to the Internet near you.