law. Eric Goldman of the Santa Clara University School of Law wrote that while the Ninth Circuit's decision in Roommates.com was tailored to apply to a limited number of websites, he was "fairly confident that lots of duck-biting plaintiffs will try to capitalize on this opinion and they will find some judges who ignore the philosophical statements and instead turn a decision on the opinion's myriad of ambiguities". Over the next several years, a number of cases cited the Ninth Circuit's decision in Roommates.com to limit some of the Section 230 immunity to websites. Law professor Jeff Kosseff of the United States Naval Academy reviewed 27 cases in the 2015–2016 year involving Section 230 immunity concerns, and found more than half of them had denied the service provider immunity, in contrast to a similar study he had performed in from 2001 to 2002 where a majority of cases granted the website immunity; Kosseff asserted that the Roommates.com decision was the key factor that led to this change. Sex traffickingBackpage.com and FOSTA-SESTA (2012–17) Around 2001, a University of Pennsylvania paper warned that "online sexual victimization of American children appears to have reached epidemic proportions" due to the allowances granted by Section 230. Over the next decade, advocates against such exploitation, such as the National Center for Missing and Exploited Children and Cook County Sheriff Tom Dart, pressured major websites to block or remove content related to sex trafficking, leading to sites like Facebook, MySpace, and Craigslist to pull such content. Because mainstream sites were blocking this content, those that engaged or profited from trafficking started to use more obscure sites, leading to the creation of sites like Backpage. In addition to removing these from the public eye, these new sites worked to obscure what trafficking was going on and who was behind it, limiting ability for law enforcement to take action. Backpage and similar sites quickly came under numerous lawsuits from victims of the sex traffickers and exploiters for enabling this crime, but the court continually found in favor of Backpage due to Section 230. Attempts to block Backpage from using credit card services as to deny them revenue was also defeated in the courts, as Section 230 allowed their actions to stand in January 2017. Due to numerous complaints from constituents, Congress began an investigation into Backpage and similar sites in January 2017, finding Backpage complicit in aiding and profiting