With civil commitment, child-pornography offenders can be imprisoned indefinitely, lest they molest children when released. Illustration by Noma Bar / Dutch Uncle

On a Saturday night in the summer of 1998, an undercover officer logged in to a child-pornography chat room using the screen name Indy-Girl. Within minutes, a user named John introduced himself and asked her, “Are you into real life or just fantasy?” Indy-Girl said that because of the “legality of it” she had never acted on her fantasies. But she soon revealed an adventurous spirit. She was a bisexual college sophomore, she said, and had learned about sex at an early age. “My mother is very European,” she explained.

John, a thirty-one-year-old soldier stationed in Fort Campbell, Kentucky, had been using the Internet for less than a year. He began downloading child pornography after watching a television special about how Internet child porn had become epidemic. He hadn’t realized that it existed. In the five months since he’d seen the show, he had downloaded more than two thousand images from child-pornography news groups. In the anonymous chat rooms, he felt free to adopt a persona repugnant to society. He told Indy-Girl that he was a “real-life pedophile,” adding, “At least here I can come out and admit it.”

“What’s the kinkiest you’ve done?” Indy-Girl asked. John said he’d had sex with a ten-year-old while her parents were skiing, and with a fourteen-year-old at a night club in Germany. Indy-Girl recognized that she was too old for him, which was “depressing,” but she offered that her little sister liked older men. “Maybe you could intro me,” John wrote. “We could meet somewhere discreet.”

John had been in the Army for eight years, serving in Desert Storm and Bosnia, and had graduated from Penn State with a degree in history. He was thinking of leaving the service, in part because he felt picked on by other soldiers. He had been commended for having a memory for technical details, but he was also nervous, nerdy, and eager to please. At all stages of his life, he had been afflicted with the sense that he was just a “wannabe.”

Unlike other people John met online, Indy-Girl seemed to like him. After a week of conversations, she asked John if he was “r/l” (real life) about the meeting, and when he said that he was she sent him a soft-focus digital image of a girl who she said was her fourteen-year-old sister. “Now don’t be mean when you see it,” she warned. “She still has some of her baby fat, she’s kinda embarrassed.” Undeterred, John described how the three of them would enjoy one another’s company: they could have sex in the shower or in a field of flowers. He encouraged Indy-Girl to “talk dirty” and “let your imagination go wild,” but she cut him off, explaining, “I’m not the cyber type.”

She preferred to discuss the logistics of their meeting, a subject that John approached hesitantly. During the following week, Indy-Girl repeatedly expressed concern that John was avoiding her: “You’re usually so fun to chat with . . . and now . . . I feel like just . . . blaaaahhh.” She apologized for getting “a bit too gabby” and for “being so weird” and “reading into things.” John said it wasn’t her—he worked long hours and was tired. He also admitted that he wanted a relationship more than he wanted sex. He hoped to find someone who “could accept me the way I am.” “Give it a chance,” Indy-Girl encouraged. “If you like her . . . and she likes you . . . things will work out.” She added, “It’s not like she’s gonna die if you don’t.”

They decided to meet at a park in Elizabethtown, Kentucky, where they could have a picnic or go boating on the lake. Two weeks after their first conversation, John drove three hours to the appointed meeting spot. He brought lacy undergarments in his briefcase. The Military Police Investigations unit, working with the F.B.I., had recruited two young officers to play the roles of the two sisters. They arrived early, spread a blanket on the grass, and waved at John, who was sitting at a picnic table, writing in his journal.

An athletic man with light-brown hair and green eyes, John slowly walked over to the girls, who were playing with a beach ball. He offered them sodas, and they chatted about what they liked to drink—Indy-Girl said she preferred beer—and about how long the drive had taken. It was a “normal conversation,” one of the cops later wrote, until John “saw the agents approaching him, and he began backing away.” A plainclothes officer whom John had seen standing by the lake, holding a fishing pole and a tackle box, shouted at him to put his hands behind his back.

John waived his right to a lawyer, hoping to end the humiliation quickly. (His mother, for the sake of John’s two younger brothers, has asked that I not use the family’s last name.) In an interview with the agents, John confessed that he frequently downloaded child pornography, storing it on his hard drive in a folder labelled “2Young.” He was sexually attracted to the girls in the photographs, he admitted, but he had never had sexual contact with anyone below the age of eighteen. He insisted that he had invented his sexual exploits to impress Indy-Girl. According to an F.B.I. report summarizing the interview, “Everything that he said on the Internet was a lie.”

John pleaded guilty to possessing child pornography and to using the Internet to persuade a minor to have sex, and was sentenced to fifty-three months in federal prison—a relatively light sentence by today’s standards. In the past fifteen years, sentences for possession or distribution of child pornography—a federal crime, since images cross state lines—have increased in length by more than five hundred per cent. The average sentence is now a hundred and nineteen months, which is about the same as the average punishment for a physical sex crime.

Child pornography didn’t become a priority for federal law enforcement until the mid-nineties, when the Internet, offering a fun-house reflection of the spectrum of human sexuality, exposed a previously invisible population of pedophiles. Chat rooms have spawned an underground subculture in which social status is based on comprehensive libraries of images. Many users consider themselves “collectors,” trading pictures until they assemble sets that feature certain children, stars on the Internet, being sexually abused over time.

In a study of child pornography, the historian Philip Jenkins, of Penn State, found that chat rooms foster a kind of “bandit culture.” Self-described “Loli fans” see themselves as part of a subversive fraternity, unified by the pursuit of forbidden pleasures. There is a hierarchy of users: newbies, lurkers, traders, and, at the top, the pornographers themselves—“kings of the rooms,” as John told me. He said that the most sought-after images were new and made in America, and showed interracial couplings. The more taboos broken, the better. Members reinforced one another’s desires, engaging in communal rationalization. “We’d pull at evidence from the dawn of photography to prove that child sexuality was once acceptable,” John said. “Then we could say, ‘See, it’s society—not me!’ ”

When U.S. obscenity laws were first relaxed, in the fifties, no special stipulations were made for photographs of minors. “If the First Amendment means anything,” the Supreme Court wrote in 1969, “it means that a State has no business telling a man, sitting alone in his own house, what books he may read or what films he may watch.” But, by 1982, the public seemed to have discovered child sex abuse, both its trauma and its prevalence. The Supreme Court made child pornography an exception to the First Amendment, since “a child has been physically or psychologically harmed in the production of the work.”