ATTORNEYS REPRESENTING CRAIGSLIST told Congress on Sept. 15 that the ubiquitous web classifieds site was closing its adult section. Under intense scrutiny from the government and crusading advocacy groups, as well as state attorneys general, owner Craig Newmark famously applied the label "Censored" in his classifieds where adult advertising once appeared.

During the same September hearing of a subcommittee of the House Judiciary Committee, members of Congress listened to vivid and chilling accounts regarding underage prostitution. They heard testimony from half a dozen nonprofit executives and law enforcement officials. But the most alarming words of the day came from Deborah Richardson, the chief program officer of the Women's Funding Network (WFN), who told legislators that juvenile prostitution is exploding at an astronomical rate.

"An independent tracking study released today by the Women's Funding Network shows that over the past six months, the number of underage girls trafficked online has risen exponentially in three diverse states," Richardson claimed. "Michigan: a 39.2 percent increase; New York: a 20.7 percent increase; and Minnesota: a staggering 64.7 percent increase."

In the wake of this bombshell revelation, her disturbing figures found their way into some of the biggest newspapers in the country. USA Today, the Houston Chronicle, The Miami Herald, the Minneapolis Star Tribune, and the Detroit Free Press all repeated the dire statistics as gospel. The successful assault on Craigslist was followed by a cross-country tour by Richardson and the WFN.

None of the media that published Richardson's astonishing numbers bothered to examine the study at the heart of her claim. If they had, they would have found what we did after asking independent experts to examine the research: It's junk science.

After all, the numbers are guesses. The data are based merely on looking at photos on the Internet. There is no science.

Eric Grodsky, a sociologist at the University of Minnesota who teaches about proper research construction, says that the study is fundamentally flawed. "The method's not clean," he says. "You couldn't get this kind of thing into a peer-reviewed journal. There are just too many unanswered questions about [the WFN's] methodology."

Ric Curtis, the chairman of the anthropology department at John Jay College of Criminal Justice in New York City, led a Justice Department–funded study on juvenile prostitution in New York City in 2008. He's highly skeptical of the WFN study's claims. "I wouldn't trust those numbers," he says. "This new study seems pretty bogus."

In fact, the group behind the study admits as much. It's now clear it used fake data to deceive the media and lie to Congress. And it was all done to score free publicity and a wealth of public funding.

"We pitch it the way we think you're going to read it and pick up on it," says Kaffie McCullough, the director of Atlanta-based antiprostitution group A Future Not a Past. "If we give it to you with all the words and the stuff that is actually accurate — I mean, I've tried to do that with our PR firm, and they say, 'They won't read that much.'"

A Future Not a Past is a product of the Atlanta Women's Foundation, the Juvenile Justice Fund, and Harold and Kayrita Anderson's foundation. To measure the amount of juvenile prostitution in the state, the consortium hired the Schapiro Group, an Atlanta business-consulting operation.

The Schapiro Group members weren't academic researchers, and had no prior experience studying prostitution. In fact, the group was best known for research paid for by the American Chamber of Commerce Executives. The study found — surprise — that membership in the Chamber of Commerce improves businesses' image.

The consultants came up with a novel, if not very scientific, method for tabulating juvenile prostitutes: They counted pictures of young-looking women on online classified sites.

"That's one of the first problems right there," Grodsky says. "These advertisers are in the business of making sales, and there's a market for young-looking women. Why would you trust that the photographs are accurate?"

In other words, the ads, like the covers of women's magazines, are relentlessly promoting fantasy. Anyone who has tried online dating understands the inherent trouble in trusting photographs.

Even if the person placing the advertisement is the one in the picture, there's no telling how old the photo is, says David Finkelhor, the director of the Crimes Against Children Research Center at the University of New Hampshire. "How do you know when the pictures were taken?" he asks. "It's not illegal for an 18-year-old who's selling sex to put up a picture of herself from when she was 16."

And if, for the sake of argument, the photos were an accurate portrayal, how do you train those viewing the photographs to guess the correct age? In fact, you don't.

Before conducting its full study, the Schapiro Group tested the accuracy of its method in a sample of 100 observers. At one point, observers are described as a "random sample." Elsewhere, they are described as "balanced by race and gender." These 100 adults were shown pictures of teenagers and young adults whose ages were known, and were asked to guess whether they were younger than 18.

"The study showed that any given 'young'-looking girl who is selling sex has a 38 percent likelihood of being under age 18," reads a crucial passage in the study's explanation of methodology. "Put another way, for every 100 'young'-looking girls selling sex, 38 are under 18 years of age. We would compute this by assigning a value of .38 to each of the 100 'young' girls we encounter, then summing the values together to achieve a reliable count."

This is dense gibberish posing as statistical analysis.

When the team went on to conduct its full statewide study, it simply treated this 38 percent success rate as a constant. Six new observers were then turned loose to count "young-looking" sex ads on online classifieds sites like Craigslist and Backpage. That total count was then multiplied by .38 to come up with a guesstimate of how many children were being trafficked.