FOSTA creates the crimes of “promotion or facilitation of prostitution” and “reckless disregard of sex trafficking,” with accompanying penalties of fines and prison terms spanning 10 to 25 years. It’s being hailed by most anti-trafficking advocates as long overdue because Congress is finally sending a cautionary message to ISPs that sell sex on their sites. The Act is a promising first step in that it may have a chilling effect on the most egregious players, like Backpage, which knowingly exploits children on its website for its own financial gain. According to the Senate’s Permanent Subcommittee on Investigations, Backpage’s CEO Carl Ferrer knew full well that he was assisting pimps in selling children. In one instance, Ferrer exchanged emails with an advertiser named “Urban Pimp” and gave the pimp his personal assurance that the pimp’s sex ads would be published. All of this happened while Backpage’s profits continued to skyrocket into the hundreds of millions, primarily due to its sex ads.

Given Backpage’s seemingly obvious involvement in sex trafficking, advocates hope that this new Act will finally be the sword sharp enough to pierce the shield of immunity that Backpage has long been hiding behind. Specifically, Backpage (and similar ISPs) have successfully argued that they are protected by Section 230 of the Communications Decency Act, which provides that ISPs cannot be treated as “speakers” or “publishers” of any information provided by “another content provider.” FOSTA seeks to subvert ISPs’ claims of immunity and hold them accountable.

However, even in cases as egregious as those involving Backpage, criminal prosecutors will have formidable hurdles to overcome before securing convictions. The Act requires that the ISP have the intent to promote or facilitate prostitution or engage in sex trafficking. Because ISPs are publishing ads that are primarily drafted by third parties, this may be quite difficult to prove. ISPs will likely contend that, while they may have inadvertently assisted traffickers on their sites, this assistance wasn’t intentional. Thus, prosecutors will have the arduous burden of demonstrating that the ISPs knew that pimps were peddling flesh on their websites and, even with this knowledge, the ISPs assisted pimps in exploiting their victims.

Also, while FOSTA allows for civil damages for sex-trafficking victims, the Act severely limits the instances where victims can recover. FOSTA mandates that civil damages are appropriate only where the ISP had “responsibility for the creation or development of all or part of the information or content” in the ad. Requiring victims to make this showing could likely prove a gargantuan task. ISPs will contend that, while they may have moderators who minimally edit the ads, they are not responsible for creation of content. Congress’s addition of this content requirement thus leaves victims on questionable footing.

Finally, FOSTA’s passage could lead to some unintended consequences. Craigslist announced on Friday that it will be taking down its “Personals” section, because it cannot “jeopardize” its overall site. There is a question as to what will happen if other websites follow suit. Elizabeth McDougall, Backpage’s lawyer, had a dire prediction that this sex-advertising content could migrate to “what are known as the ‘black hat’ websites, the underground websites, and ultimately the off-shore websites” outside the jurisdiction of the United States. This is a real concern among law enforcement and advocates.

While FOSTA is a move forward in the attempt to curb Internet sex trafficking, how successful it will be in doing so remains to be seen. Many advocates hope that Congress will revisit this issue and broaden the scope of potential criminal and civil liability for ISPs to encourage them to play a more active role in curbing the growing tide of sex trafficking on the Internet.

Maureen Guirguis Kenny is the co-founder and co-director of the Human Trafficking Law Clinic at Case Western Reserve University’s School of Law.