In response, Myspace, the web’s largest social media platform at the time, gave the boot to some 90,000 convicted sex offenders. Facebook, meanwhile, took steps to prevent underage users from sharing personal information with strangers. Craigslist started requiring that anyone who posted an ad in its Erotic Services section provide a verified phone number and pay a fee by credit card. It also hired attorneys to moderate ads.

For some officials, though, these changes weren’t enough. In early 2009, Thomas Dart, the sheriff of Cook County, Illinois, sued Craigslist for facilitating prostitution. “Missing children, runaways, abused women, and women trafficked in from foreign countries are routinely forced to have sex with strangers because they’re being pimped on Craigslist,” he said. “I could make arrests off Craigslist 24 hours a day, but to what end? I’m trying to go up the ladder.” That same spring, tabloids across the country were awash in headlines about the “Craigslist killer,” a young man in Boston who’d responded to a massage ad on the site, then murdered the woman who posted it.

A federal judge in Chicago quickly tossed Dart’s case, citing Section 230. But Craigslist eventually surrendered anyway. On the night of September 3, 2010, it quietly covered its Adult Services section with the word censored. Two weeks later, in testimony before Congress, Craigslist execs explained that they’d done their best to address their critics’ complaints; now, it seemed, they just wanted out of the headlines. They also warned that law enforcement was losing a valuable partner in the fight against trafficking. Yet Ernie Allen, the lanky Kentuckian who ran the National Center for Missing and Exploited Children, saw this as a necessary step. “Some of this problem will migrate to other areas,” he said, “but frankly that’s progress.”

Allen’s prediction was right. In the wake of Craigslist’s capitulation, the sex trade did indeed shift to other sites. There were many to choose from—myRedBook, Naughty Reviews, Cityvibe, Rentboy—but Backpage was the chief beneficiary. Larkin sent around an email advising his employees to expect “a deluge” of adult ads and reminding them that, “like it or not,” such ads “are in our DNA.” Lacey says he remained focused, as always, on the editorial side—though he had “no problem” seeing the ads “take off like they did.” Ferrer, meanwhile, seemed only too happy to inherit Craigslist’s share of the adult market, even if that meant assuming its place in the crosshairs. “It is an opportunity for us,” he wrote in an email. “Also a time when we need to make sure our content is not illegal.”

Backpage was already getting into hot water. A girl in Missouri had sued the site in mid-September, alleging that she’d been pimped out at the age of 14 and that Backpage had willfully “failed to investigate for fear of what it would learn.” She claimed, without clear evidence, that the site’s operators “had a strong suspicion” she was underage. Ultimately, a federal magistrate dismissed her case. The situation was tragic, he said, but Backpage was protected under Section 230. The girl needed to sue her pimp.

On October 18, Backpage announced on its blog that it had retained Hemanshu Nigam, a former federal prosecutor who specialized in sex crimes and child abuse, to develop a “holistic” safety program. Nigam sat on the board of the National Center for Missing and Exploited Children and had done similar work for Myspace. In the months that followed, Nigam and his new clients met repeatedly with representatives from anti-trafficking organizations. They discussed changes to Backpage’s site architecture, moderation practices, and content policies. The organizations suggested, for instance, that users should be prevented from employing search terms such as “incest” or “Lolita,” since these might “indicate illegal activity.” Backpage moderators, meanwhile, should be on the lookout for “ads written from masculine perspective,” particularly if they employed the euphemism “new in town,” which “is often used by pimps who shuttle children to locations where they do not know anyone and cannot get help.”

“You want to sue us, bring your lunch pail, ’cause we gonna be awhile.”

By late January 2011, Backpage had implemented many of the recommendations: It had banned photographs with nudity, drawn up a list of “inappropriate terms,” beefed up its vetting process, and begun referring “ads containing possible minors” directly to Allen’s staff. Ferrer also worked closely with the authorities. According to a Justice Department memo from 2012, “unlike virtually every other website that is used for prostitution and sex trafficking, Backpage is remarkably responsive to law enforcement requests and often takes proactive steps to assist in investigations.” A later memo noted that “even Ernie Allen believed that Backpage was genuinely trying to rid its site of juvenile sex trafficking.”