Analysis The US House of Representatives has overwhelmingly passed a bill aimed at tackling online sex traffickers, but which critics warn will have little effect on curbing the vile trade and could instead undermine free speech on the internet.

The (Allow States and Victims to) Fight Online Sex Trafficking Act (FOSTA) – which included a Senate version of the same bill called Stop Enabling Sex Traffickers Act (SESTA) as an amendment – passed by 388 votes to just 25. It will now move to the Senate where passage is less certain but still likely.

Despite pretty much everyone agreeing with its stated goal – shutting down people who sell human beings online – the law has proved controversial because of the way it went about it: removing legal protections from online platforms.

Under FOSTA-SESTA, Section 230 of the Communications Decency Act (CDA) will be amended to note that websites can be prosecuted if they engage in the "promotion or facilitation of prostitution."

While that may seem uncontroversial to some (but not others), any change to Section 230 has been vigorously opposed by tech companies and free speech advocates out of concern that it will inevitably lead to efforts to insert more exceptions. As such, Section 230 has been guarded with almost religious zeal.

Those protective efforts are understandable: there is a strong argument to be made that Section 230 has been foundational to the success of countless internet companies, from Wikipedia to Google to eBay.

You could even argue that Section 230 is the reason that the United States continues to dominate the online world: companies in other countries don't enjoy the same broad-based legal protection and so have to be far more careful in their system's design and management.

In addition, intellectual property lawyers have been trying for 20 years to find a way to make online platforms liable for pirated content, often using people's fear over other issues – like terrorism or child abuse images – to drive their own agenda. The spirited defense of Section 230 has largely blocked that effort.

Ideology

However, the overwhelming approval of FOSTA-SESTA in the House also indicates another difficult fact: that protection of Section 230 at all costs has become an ideology that has led to some dubious stances.

Opponents to the bill, most notably the EFF and Center for Democracy and Technology (CDT), point out that there is nothing to stop federal prosecutors from going after internet companies that host sex trafficking ads right now; it is, after all, a federal crime.

But backers of the measure point out that a recent court case around the website that this entire effort stemmed from – Backpage.com – decided that the company was protected from lawsuits brought against it by children that had been trafficked through the site. How? Because of Section 230.

In a further unpleasant reality, a long list of child protection experts noted in a letter [PDF] that the same organizations arguing against FOSTA-SESTA "have vigorously and consistently intervened in Backpage cases, including those filed by children, to support the position and claims of Backpage that Section 230 protects its operations."

The determination to protect Section 230 at all costs may have gone too far.

Ah, Facebook

That at least is the conclusion Facebook appears to have reached. Facebook is a powerful actor in the internet industry and was responsible in large part both for the tech industry's opposition to SESTA-FOSTA and then its sudden and unexpected capitulation.

Having been hauled in front of several Congressional committees and threatened with regulation over its failure to prevent the spread of fake news and its acceptance of paid-for divisive ads by Russian agents, the company was desperate to get lawmakers back on side.

And so, despite a fierce defense of Section 230 by industry body the Internet Association, the group suddenly changed it tune and said it would support – or, at least, not oppose – SESTA.

The price extracted for removing its opposition was the inclusion of a single word in the Senate version of the law: "knowingly." Under the Senate version, online platforms would have to be "knowingly assisting, supporting, or facilitating" prostitution to be found legally liable.

That means that if a company is informed of such illegal content and does nothing about it then it can become legally liable for that.

That is a compromise that Facebook is willing to deal with, although many other technology companies are reportedly furious that the Internet Association capitulated. In part this is on ideological grounds, and in part on a pragmatic problem – they will have to make sure their complaint systems work quickly and efficiently or they face lawsuits.

Opponents to SESTA-FOSTA have painted worst-case scenarios as being a virtual certainty: companies will have to screen all content, reducing free speech; online companies will be hit with massive class action lawsuits; the next Facebook or Yelp won't even bother to launch because of the looming threat of legal action.