So what do predators discuss online? In short, everything, says Kurt. From the TV shows that have the most attractive children to pointers on how to lure a child into sexual acts, not much is off limits.

According to Kurt, many online predators believe children have a desire to have sex with adults and that other adults—like parents—force them to "deny their desires."

A lot of what passes for advocacy, Kurt says, is simply a smoke screen in these communities. The crime takes place when fantasies translate into real, daily life, he says.

During his investigation, Kurt found predators may have acted upon fantasies in one place where children should feel safe—the classroom. Kurt was shocked to learn through his research that the most common job for pedophiles is teaching. He says one principal said in an online chat that he met his first "YF"—a popular abbreviation for "Young Friend"—when he was sent to his office for discipline.

"They're aware that people can be watching, and even so, they are very open about the nature of what they're doing," Kurt says.

A reporter catches predators in the act. »