But she advised her employers against having a presence in Second Life, at least for now, not because of the sex but because they're a small company, with only 350 employees, and not enough of their customers were in Second Life now. "Also, quite frankly, I'm afraid it would be a distraction," she said.

The Sexual Philosophy Of Second Life Founder Philip Rosedale

When Linden Lab launched Second Life in 2003, they had a choice whether to allow sex. An older virtual world, There.com, doesn't allow it; they keep things family-friendly.

Allowing sex in Second Life is part of Linden Lab's overall philosophy that Second Life residents should be free to create their own experience in-world.

"We believed that freedom was fundamental to the environment and freedom is not something you can split hairs on. Second Life, like the Internet, is open to all, and what people want to do there is their own decision," Rosedale said in an interview we conducted in Second Life using the voice beta software.

Moreover, while Linden Lab and the Second Life community bend over backward to protect residents' privacy, that protection isn't universal. Some users volunteer their credit-card information to buy products and services in Second Life. Linden Lab keeps track of users' IP numbers. And Linden Lab is willing to turn that information over to law enforcement authorities to help investigate violations of the law, Rosedale said.

"Everything in Second Life is marked with your identity and name," he said. "If you break the law in your locality in real life, and we can facilitate people going after you, we have no problem with that."

Linden Lab has taken harsh criticism from residents for the ageplay crackdown, and for cooperating in the investigation, but Rosedale stands by the decision.

He also questions the idea, put forward by Widdershins, Murphy, and others, that sex in Second Life is anonymous and without consequence.

Many people in Second Life -- especially in the cybersex community -- prefer to use the service without disclosing information about their real-life identities. In that respect, Second Life is anonymous.

But people do forge identities and relationships in Second Life. Friendship in Second Life involves real emotions, just as there can be a real emotional connection between pen pals who have never met.

Sex in Second Life often involves a relationship that evolves over time, Rosedale said.

"A lot of the sex relationships in Second Life are driven more by lengthy, meaningful discussions," Rosedale said. "People have sex in Second Life because they have incredibly deep relationships, not just because they want to have sex."

He added, "It isn't really an anonymous environment. It's really no more or less anonymous than the real world. If you want to travel to a faraway city where no one knows you and go into a strip club, that's anonymous too."

Second Life sex is a by-product of the sense of "presence" you get in-world, Rosedale said. That's something that's difficult to convey to anybody who hasn't used Second Life for more than a few hours. Presence pervades every element of Second Life, not just sex. When you're logged in to Second Life and your avatar is sitting across a table from another avatar, and you're discussing politics, it doesn't feel like you're alone at your computer -- you have the illusion of really talking to another person across a table.

And sometimes when people are talking across a table, that leads to sex. In real life and in Second Life, too.

Mitch Wagner's Second Life avatar is Ziggy Figaro.