This article first appeared on Nov. 10 on Law.com.

At the Electronic Frontier Foundation (EFF), we are proud to be ardent defenders of §230. Even before §230 was enacted in 1996, we recognized that all speech on the Internet relies upon intermediaries, like ISPs, web hosts, search engines, and social media companies. Most of the time, it relies on more than one. Because of this, we know that intermediaries must be protected from liability for the speech of their users if the Internet is to live up to its promise, as articulated by the U.S. Supreme Court in ACLU v. Reno, of enabling “any person … [to] become a town crier with a voice that resonates farther than it could from any soapbox“ and hosting “content … as diverse as human thought.”

As we hoped—and based in large measure on the strength of the Fourth Circuit’s decision in Zeran—§230 has proven to be one of the most valuable tools for protecting freedom of expression and innovation on the Internet. In the past two decades, we’ve filed well over 20 legal briefs in support of §230, probably more than on any other issue, in response to attempts to undermine or sneak around the statute. Thankfully, most of these attempts were unsuccessful. In most cases, the facts were ugly—Zeran included. We had to convince judges to look beyond the individual facts and instead focus on the broader implications: that forcing intermediaries to become censors would jeopardize the Internet’s promise of giving a voice to all and supporting more robust public discourse than ever before possible.

This remains true today, and it is worth remembering now, in the face of new efforts in both Congress and the courts to undermine §230’s critical protections.

Attacks on §230: The First 20 Years

The first wave of attacks on §230’s protections came from plaintiffs who tried to plead around §230 in an attempt to force intermediaries to take down online speech they didn’t like. Zeran was the first of these, with an attempt to distinguish between “publishers” and “distributors” of speech that the Fourth Circuit rightfully rejected. As we noted above, the facts were not pretty: the plaintiff sought to hold AOL responsible after an anonymous poster used his name and phone number on an AOL message board to indicate—incorrectly—that he was selling horribly offensive t-shirts about the Oklahoma City bombing. The court rightfully held that §230 protected against liability for both publishing and distributing user content.

The second wave of attacks came from plaintiffs trying to deny §230 protection to ordinary users who reposted content authored by others—i.e., an attempt to limit the statute to protecting only formal intermediaries. In one case, Barrett v. Rosenthal, the attackers succeeded at the California court of appeals. But in 2006, the California Supreme Court ruled that §230 protects all non-authors who republish content, not just formal intermediaries like ISPs. This ruling—which was urged by EFF as amicus along with several other amici—still protects ordinary bloggers and Facebook posters in California from liability for content they merely republish. Unsurprisingly, the California Supreme Court’s opinion included a four-page section dedicated entirely to Zeran.

Another wave of attacks, also in the mid-2000s, came as plaintiffs tried to use the Fair Housing Act to hold intermediaries responsible when users posted housing advertisements that violated the law. Both Craigslist and Roommates.com were sued over discriminatory housing advertisements posted by their users. The Seventh Circuit, at the urging of EFF and other amici, held that §230 immunized Craigslist from liability for classified ads posted by its users—citing Zeran first in a long line of cases supporting broad intermediary immunity. Despite our best efforts, however, the Ninth Circuit found that §230 did not immunize Roommates.com from liability if, indeed, it was subject to the law. The majority opinion ignored both us and Zeran, citing the case only once in a footnote responding to the strong dissent. It found that Roommates.com could be at least partially responsible for the development of the ads because it had forced its users to fill out a questionnaire about housing preferences that included options that the plaintiffs asserted were illegal. The website endured four more years of needless litigation before the Ninth Circuit ultimately found that it hadn’t actually violated any anti-discrimination laws at all, even with the questionnaire. The court left its earlier opinion intact, however, and we were worried the exception carved out in Roommates.com would wreak havoc on §230’s protections. It luckily hasn’t been applied broadly by other courts—undoubtedly thanks in large part to Zeran’s stronger legal analysis and influence.

The Fight Continues

We are now squarely in the middle of a fourth wave of attack—efforts to hold intermediaries responsible for extremist or illegal online content. The goal, again, seems to be forcing intermediaries to actively screen users and censor speech. Many of these efforts are motivated by noble intentions, and the speech at issue is often horrible, but these efforts also risk devastating the Internet as we know it.

Some of the recent attacks on §230 have been made in the courts. So far, they have not been successful. In these cases, plaintiffs are seeking to hold social media platforms accountable on the theory that providing a platform for extremist content counts as material support for terrorism. Courts across the country have universally rejected these efforts. The Ninth Circuit will be hearing one of these cases, Twitter v. Fields, in December.

But the current attacks are unfortunately not only in the courts. The more dangerous threats are in Congress. Both the House and Senate are considering bills that would exempt charges under federal and state criminal and civil laws related to sex trafficking from §230’s protections—the Stop Enabling Sex Trafficking Act (S. 1693) (SESTA) in the Senate, and the Allow States and Victims to Fight Online Sex Trafficking Act (H.R. 1865) in the House. While the legislators backing these laws are largely well meaning, and while these laws are presented as targeting commercial classified ads websites like Backpage.com, they don’t stop there. Instead, SESTA and its house counterpart punish small businesses that just want to run a forum where people can connect and communicate. They will have disastrous consequences for community bulletin boards and comment sections, without making a dent in sex trafficking. In fact, it is already a federal criminal offense for a website to run ads that support sex trafficking, and §230 doesn’t protect against prosecutions for violations of federal criminal laws.

Ultimately, SESTA and its house counterpart would impact all platforms that host user speech, big and small, commercial and noncommercial. They would also impact any intermediary in the chain of online content distribution, including ISPs, web hosting companies, websites, search engines, email and text messaging providers, and social media platforms—i.e., the platforms that people around the world rely on to communicate and learn every day. All of these companies come into contact with user-generated content: ads, emails, text messages, social media posts. Under these bills, if any of this user-generated content somehow related to sex trafficking, even without the platform’s knowledge, the platform could be held liable.

Zeran’s analysis from 20 years ago demonstrates why this is a huge problem. Because these bills would have far-reaching implications—just as every other legislative proposal for limiting §230—they would open Internet intermediaries, companies, nonprofits, and community supported endeavors alike to massive legal exposure. Under this cloud of legal uncertainty, new websites, along with their investors, would be wary of hosting open platforms for speech—or of even starting up in the first place—for fear that they would face crippling lawsuits if third parties used their websites for illegal conduct. They would have to bear litigation costs even if they were completely exonerated, as Roommates.com was after many years. Small platforms that already exist could easily go bankrupt trying to defend against these lawsuits, leaving only larger ones. And the companies that remained would be pressured to over-censor content in order to proactively avoid being drawn into a lawsuit.

EFF is concerned not only because this would chill new innovation and drive smaller players out of the market. Ultimately, these bills would shrink the spaces online where ordinary people can express themselves, with disastrous results for community bulletin boards and local newspapers’ comment sections. They threaten to transform the relatively open Internet of today into a closed, limited, censored Internet. This is the very result that §230 was designed to prevent.

Since Zeran, the courts have recognized that without strong §230 protections, the promise of the Internet as a great leveler—amplifying and empowering voices that have never been heard, and allowing ideas to be judged on their merits rather than on the deep pockets of those behind them—will be lost. Congress needs to abandon its misguided efforts to undermine §230 and heed Zeran’s time-tested lesson: if we fail to protect intermediaries, we fail to protect online speech for everyone.