Civil liberties activists long warned that the federal government must adopt “net neutrality” requirements that prevent broadband companies from charging websites for prioritized access to their lines or risk the loss of freedom and openness online. Yet, the Federal Communications Commission repealed Obama-era net neutrality regulations a year ago, and the internet did not break.

Unfortunately, there is a growing movement in Washington to change a technology law that has received far less attention than net neutrality but is more central to how the internet operates. The outcome of this debate actually could break the internet as we know it or, at the very least, change the playing field for online speech.

In 1996, as part of an overhaul of U.S. telecommunications laws, Congress quietly added a tiny provision that became known as Section 230 of the Communications Decency Act. The law states that online platforms cannot be treated as the publisher of information that is provided by a third party. This means that Yelp cannot be sued for user reviews, Twitter is not responsible for tweets, and Wikipedia is immune from lawsuits stemming from user-written articles.

Courts have interpreted Section 230 quite broadly in the past two decades, smoothing the way for social media, search engines, online forums and any other platforms that rely on user-created content. Section 230 provides the most far-reaching protections for online platforms in the world, and it is no coincidence that many of the most successful internet companies are based in the United States.

The platforms are free to set their own community rules, and they do not need to fear liability for their moderation (or lack thereof). I spent more than two years writing a book about the history of Section 230. The book, which will be published in the spring, is titled “The Twenty-Six Words That Created the Internet” (Cornell University Press). The title is not an exaggeration. Section 230’s simple but sweeping immunity has shaped the free and open internet that we know today.

Section 230 has resulted not only in economic prosperity for technology companies but in protections for online speech that far exceed those of the First Amendment. Unfortunately, Section 230 also has allowed platforms to dodge responsibility, even if they failed to adequately police their sites for harmful or illegal user content. Even if a site encourages its users to defame others, Section 230 likely will protect the operator from a lawsuit.

Section 230 has largely flown under the radar in Washington until recently. That changed due to a number of high-profile incidents on social media, such as the distribution of fake news, ISIS propaganda and discriminatory job advertisements. Platforms also have banned some political commentators for violating their policies on hate speech and harassment, attracting criticism for censoring speech. A growing group of advocates and policymakers wants to eliminate Section 230 entirely or scale it back significantly. Indeed, at a hearing this month about Google’s business practices, Congress members criticized the broad protections that Section 230 provides to platforms such as Google.

What would happen to the internet if Section 230 disappeared? The most visible challenge to Section 230 came after a 2016 federal appellate court ruled that victims of sex trafficking could not sue Backpage, the site where they were sold by pimps. Congress responded earlier this year by amending Section 230 to allow certain sex trafficking-related civil and state criminal claims against platforms. Two days after Congress passed the Section 230 amendment, Craigslist shut down its online personals site. “Any tool or service can be misused,” the site wrote. “We can't take such risk without jeopardizing all our other services, so we are regretfully taking craigslist personals offline.”

The internet will survive without online personal ads. But eliminating Section 230 entirely likely would extend that chilling effect to social media, consumer review sites, Wikipedia and just about every other site and app that is a centerpiece of online life. Just as Craigslist took a risk-averse approach after the sex trafficking amendment to Section 230, any rational platform would severely curtail user content in a Section 230-free world.

Perhaps the public and lawmakers will determine that the social harms of Section 230 outweigh the benefits of the free speech that have come to define the internet in the United States. But the frank discussion must occur before Congress considers further changes to Section 230.

After the netroots community’s clamorous opposition to changes to the FCC’s net neutrality regulations, it is surprising to see activists’ relative indifference about changes to Section 230. Perhaps the large platforms have angered all sides of the political spectrum with their lack of transparency, arrogance and imperfect moderation practices. Or maybe Section 230 just isn’t as interesting as net neutrality. But its impact on the internet is exponentially greater.

Jeff Kosseff (jkosseff@gmail.com) is an assistant professor of cybersecurity law at the U.S. Naval Academy and author of the forthcoming book “The Twenty-Six Words That Created the Internet” (Cornell University Press, 2019). The views expressed are only his and do not represent the Naval Academy, Department of Navy or Department of Defense.