Washington (CNN) The Senate voted Wednesday to approve an anti-sex-trafficking bill that would allow victims of sex trafficking to seek justice against online platforms that knowingly facilitate the act, a move that prosecutors, victims and anti-trafficking activists are heralding as an essential step in cracking down on the crime.

But others, such as tech advocacy groups, fear the limitations it could place on free speech on the internet.

The bill passed 97-2, and now goes to the White House for President Donald Trump's signature. The White House has expressed support for the proposal.

The bipartisan measure, the Stop Enabling Sex Traffickers Act, would create an exception to Section 230 of the Communications Decency Act to allow victims of sex trafficking to sue websites that enabled their abuse. The House version passed with an overwhelming majority from both parties by 388-25 and later received an endorsement from the White House.

"The bill really moves the ball forward on an area with strong Republican and Democratic consensus at a time of horrible partisan rancor," Mark P. Lagon, the former US ambassador-at-large to combat and monitor trafficking in persons, told CNN.

Senate Majority Leader Mitch McConnell discussed the bill Tuesday, saying laws passed in the 1990s have not kept up with the changing technology.

The legislation is "designed to close a loophole in existing law that allows websites to avoid responsibility even as they knowingly facilitate trafficking. It would ensure any institutions that are party to this reprehensible practice are subject to the strict penalties they deserve," said the Kentucky Republican. "I urge each of my colleagues to join us in taking decisive action for our nation's children."

Measuring the problem

In an 18-month investigation conducted by the Permanent Subcommittee on Investigations, part of the Senate Committee on Homeland Security and Governmental Affairs, subcommittee Chairman Rob Portman, an Ohio Republican, and the committee's top Democrat, Claire McCaskill of Missouri, reported finding that Backpage.com was knowingly selling people online.

"They didn't remove the post because they didn't want to lose the revenue," Portman said on the Senate floor. "And you can imagine, this is a very lucrative business."

Under current federal law, websites cannot be held responsible for content published by third parties on their sites. That stipulation provided a jump-start that has allowed former startups like Facebook, Google and Twitter to thrive. However, the repercussions of that freedom have edged to the forefront, as sites like Facebook are facing a backlash for roles they might have unintentionally played in election meddling.

"We are now seeing the downsides of a lack of regulation that doesn't exist in any other field. You're seeing it with foreign powers meddling in our election, and you're seeing it with children being raped day in and day out," Krishna Patel, a former federal prosecutor who specialized in anti-trafficking, told CNN. "We wouldn't tolerate the recruitment of terrorists on websites."

CNN has reached out to Backpage.com for comment and has not yet received a response.

Last year, the website disputed the findings of the Senate subcommittee investigation when it announced the shuttering of adult services ads on the site.

"For years, the legal system protecting freedom of speech prevailed," Backpage said in a statement reported by The Washington Post , "but new government tactics, including pressuring credit card companies to cease doing business with Backpage, have left the company with no other choice but to remove the content in the United States."

Critics fear unintended consequences

Tech companies are concerned that the anti-trafficking bill, which changes part of the provision on freedom from liability, could stifle growth, particularly for small startups that might not be able to bear the weight of costly lawsuits.

"If this bill passes, the change that it would make will have this silencing effect on the Internet," said Elliot Harmon, an activist with the Electronic Frontier Foundation, a digital rights nonprofit.

According to Portman, the Stop Enabling Sex Traffickers Act would narrow the Communications Decency Act's broad liability protections for websites for a set of bad actors that knowingly facilitate sex-trafficking crimes. He contends that the bill protects websites that are doing the right thing.

"In fact, it preserves what's called the 'Good Samaritan' provisions of the Communications Decency Act, which protects good actors who proactively block and screen their sites for offensive material," he said in remarks on the Senate floor. "Thus, it shields them from frivolous lawsuits."

Another concern that has been posed by Alexandra F. Levy, a professor at the University of Notre Dame who specializes in anti-trafficking, is that the bill would force sites like Backpage to censor their content, taking the crimes underground and making it harder to find victims.

While it might become more difficult to find victims after sites censor their content, prosecutors argue that allowing the crimes to happen openly is not productive either.

"Yes, it's harder (to find victims).I mean, we could encourage all terrorists to recruit online, but we're not going to do that," Patel said. "We don't want to make crime readily available to people."

For Andrea Powell, executive director and co-founder of FAIR Girls, a Washington, D.C.-based anti-trafficking organization, the legislation is a long time coming. The organization has been a leader in the fight against online sex trafficking, and particularly Backpage.com for its purported role in trafficking, since 2012. She contends that because of the narrow scope of the Stop Enabling Sex Traffickers Act, the First Amendment remains intact.

"We're not trying to blanket go after any online provider where sex trafficking takes place. We want survivors who have been wronged to have better access to justice," she told CNN.

Lagon echoed the sentiment: "We're all for free speech, but that doesn't mean that information technology companies are not responsible for the way that sex trafficking is enlarged on their platforms."

Advocates for sex trade workers worry that if these sites are no longer available to post messages, sex workers will be forced to the streets, which can be more dangerous.

"It means that these platforms (like Backpage) won't be available to those who trade sex," said Kate D'Adamo, an organizer and advocate for sex trade workers. "All it does is send you into more vulnerable places, like the street, where we're talking about four to six times higher rates of violence."

Often, victims of sex trafficking are misidentified and arrested on charges of prostitution.

"SESTA does not solve the problem of sex trafficking victims and sex workers continuing to be arrested," Powell said. "While that is a deep concern, this bill is focused on creating pathways for survivors to access justice and law enforcement to specifically go after bad actors like Backpage.com."

'Website providers need to be vigilant'

Prosecutors are confident that overall the bill will provide much-needed regulation that would make it easier to crack down on sex-trafficking crime.

"Our theory is that money talks and fear of civil judgments will cause behavior to change," said Richard Schechter, senior justice adviser at Grace Farms Foundation and a former federal prosecutor. "The reality is that that will teach internet providers that if they don't monitor this, if they don't engage, they could be out of business. Website providers need to be vigilant."

Of course, advocates say there is still more to be done on the issue of sex trafficking.

"I can't stress how important this bill is. Ultimately, we've got to demand accountability. And the websites are functioning as criminal traffickers," said Swanee Hunt, chair of Demand Abolition, an anti-trafficking nonprofit. "But I don't want to lose sight of the hundreds of thousands of buyers who are going to these sites."

The bill, which has the support of the White House, is sponsored by 68 senators and is expected to pass when it gets a vote.