Last week, Somaly Mam resigned from the foundation she co-founded seven years ago. Mam, dubbed "the James Frey of anti–sex trafficking activism" by my colleage Elizabeth Nolan Brown, achieved her fame by telling the world that she had been forced to work in a Cambodian brothel as a child and that her group rescued girls who had suffered a similar fate. For several years, journalists have been questioning many of Mam's claims. Those investigations culminated last month in a devastating Newsweek piece that showed Mam had lied repeatedly both about her own life and about the experiences of the people she says she rescued. One of the latter, Newsweek reports, "confessed that her story was fabricated and carefully rehearsed for the cameras under Mam's instruction, and only after she was chosen from a group of girls who had been put through an audition." In March, the Somaly Mam Foundation launched an investigation of its own, which ended with Mam stepping down. Her carefully cultivated image as a victim-turned-savior had fallen apart.

Yesterday a second shoe started to drop. Mam's greatest champion in the American press has been Nicholas Kristof of The New York Times, who has praised the woman in incandescent terms and even went for a ride-along on one of her brothel raids. In a brief blog post published Monday, Kristof says he doesn't "know quite what to think" about the controversy, and that he's "reluctant to be an arbiter of her back story when I just don't know what is true and false." He offers some reasons one might doubt a few (hardly all) of the accusations against Mam, and he promises to "poke around" for the facts. All in all a rather weak response, given that some of these charges have been out there for years now. This surely isn't the first time Kristof has heard any of them, though it may be the first time he's had to think about taking them seriously.

While Kristof cautiously pokes around, the rest of us should probe more deeply. As I never tire of saying, a legend that catches on tells us something about the worldview of the people who believe it, even if the story itself is largely or entirely false. So why do people like Kristof swallow deceptions like Mam's? Where do these tales get their power, and what are their consequences?

Mam was in the business of producing captivity narratives, and the captivity narrative is a primal storyline in American culture. As early as 1682, settlers were publishing accounts of being held prisoner by Indians, establishing a formula that has manifested itself in tales ranging from cowboy novels to Vietnam movies. In Regeneration Through Violence, the literary historian Richard Slotkin described the archetypal captivity scenario:

a single individual, usually a woman, stands passively under the strokes of evil, awaiting rescue by the grace of God….In the Indian's devilish clutches, the captive had to meet and reject the temptation of Indian marriage and/or the Indian's "cannibal" Eucharist. To partake of the Indian's love or his equivalent of bread and wine was to debase, to un-English the very soul.

This is by no means an exclusively American phenomenon. (Before anybody was producing captivity narratives in the New World, Englishmen were printing memoirs of their alleged experiences in the hands of the Barbary pirates.) But the story is well ingrained in our culture, and it is tied up—as Slotkin's reference to "the Indian's love" implies—with a bunch of sexual anxieties. One particularly lurid branch of the captivity-story family tree is the series of white slavery narratives that flourished in the early 20th century. These books, films, and articles offered sensationalist accounts of women coerced into prostitution, often by the agents of a vast trafficking conspiracy.

Those stories offered a deeply distorted view of prostitution as it was actually practiced, but they were widely believed, and they had a lasting impact not just on American culture but on American law. As Thaddeus Russell recently wrote in Reason, the moral panic that fed and was fed by the white slavery narratives

helped create, expand, and strengthen the police powers of an array of government agencies. Since the onset of the panic, those agencies have imprisoned and sterilized hundreds of thousands of women who worked as prostitutes, taken their children from them, forced them onto the streets and into dependent relationships with male criminals, and made their jobs among the most dangerous in the world. Those same government agencies also prosecuted black, Jewish, Latino, and Asian men for simply having intimate relations with white women; tightened restrictions on immigration; established precedents for some of the worst government violations of privacy and civil liberties in American history; and formed the basis of the modern surveillance state.

Needless to say, none of this history in itself means that Mam made up her tales. Captivity is obviously real. Many Indian captivity tales were written by people who really had been held prisoner by native tribes, and coerced prostitution certainly does exist. We know Mam is a fabulist because of the detailed reporting exposing her lies, not because those lies took a familiar form.

The point is that the captivity narrative is a genre. If you do invent a story, it provides a resonant formula for your deceptions. And that formula is going to be particularly resonant for someone like Kristof, a man who seems especially susceptible to the white-savior fantasies that tales like this tend to foster.

In his blog post, Kristof worries that "the debate about Somaly's back story will overtake the imperative of ending the trafficking of young teenagers into brothels"; he stresses that "this is about more than one woman." He does not ponder whether any of those additional women have been injured by the lies he helped to spread. Stopping sexual slavery is obviously a worthy goal, but the single-minded focus on ending traffic "into brothels" has diverted resources from preventing much more common forms of coerced labor—especially since the crackdown has frequently fallen on sex workers who were not in fact being trafficked. "Some of the 'victims' whom Ms. Mam said she saved then attempted to escape from her shelters," Melissa Gira Grant notes in a New York Times op-ed, "only to have her claim to the press that they had been 'kidnapped.'" (Here too we see echoes of earlier captivity legends. Books like Maria Monk's Awful Disclosures, a 19th-century hoax by an alleged ex-nun who claimed that convents were sexual prisons, sometimes led Protestants to raid nunneries to "free" the women who lived there.)

As Grant points out, the

International Labor Organization estimates that more than three times as many people are trafficked into work like domestic, garment and agricultural labor than those trafficked for sex. I've interviewed human-rights advocates in Phnom Penh since 2007, and they raised concerns about Ms. Mam's distortion of this reality. Her portrayal of all sex workers as victims in need of saving encouraged raids and rescue operations that only hurt the sex workers themselves. In 2008, Cambodia enacted new prohibitions on commercial sex, after the country was placed on a watch list by the State Department. In brutal raids on brothels and in parks, as reported by the Asia Pacific Network of Sex Workers in a 2008 documentary, women were chased down, detained and assaulted. The State Department commended Cambodia for its law and removed the country from the watch list. Human Rights Watch later conducted interviews with 94 sex workers in Cambodia for a 2010 report. "Two days after my arrival, I was caught when I tried to escape," one woman said. "Five guards beat me up. When I used my arms to shield my face and head from their blows, they beat my arms. The guard threatened to slit our throats if we tried to escape a second time, and said our bodies would be cremated there." She was describing a "rescue" and detention at the Prey Speu Social Affairs center near Phnom Penh.

Like I said, some captivity stories are true. They just aren't always the ones you've been hearing. In trying to expose one form of abuse, Nicholas Kristof enabled another.