President Trump’s recent threat to “unequivocally VETO” the National Defense Authorization Act (NDAA) if it doesn’t include a repeal of Section 230 may represent the final attack on online free speech of his presidency, but it’s certainly not the first. The NDAA is one of the “must-pass” bills that Congress passes every year, and it’s absurd that Trump is using it as his at-the-buzzer shot to try to kill the most important law protecting free speech online. Congress must reject Trump’s march against Section 230 once and for all.

Under Section 230, the only party responsible for unlawful speech online is the person who said it, not the website where they posted it, the app they used to share it, or any other third party. It has some limitations—most notably, it does nothing to shield intermediaries from liability under federal criminal law—but at its core, it’s just common-sense policy: if a new Internet startup needed to be prepared to defend against countless lawsuits on account of its users’ speech, startups would never get the investment necessary to grow and compete with large tech companies. 230 isn't just about Internet companies, either. Any intermediary that hosts user-generated material receives this shield, including nonprofit and educational organizations like Wikipedia and the Internet Archive.

Section 230 is not, as Trump and other politicians have suggested, a handout to today’s dominant Internet companies. It protects all of us. If you’ve ever forwarded an email, Section 230 protected you: if a court found that email defamatory, Section 230 would guarantee that you can’t be held liable for it; only the author can.

If you’ve ever forwarded an email, Section 230 protected you.

Two myths about Section 230 have developed in recent years and clouded today’s debates about the law. One says that Section 230 somehow requires online services to be “neutral public forums”: that if they show “bias” in their decisions about what material to show or hide from users, they lose their liability shield under Section 230 (this myth drives today’s deeply misguided “platform vs. publisher” rhetoric). The other myth is that if Section 230 were repealed, online platforms would suddenly turn into “neutral” forums, doing nothing to remove or promote certain users’ speech. Both myths ignore that Section 230 isn’t what protects platforms’ right to reflect any editorial viewpoint in how it moderates users’ speech—the First Amendment to the Constitution is. The First Amendment protects platforms’ right to moderate and curate users’ speech to reflect their views, and Section 230 additionally protects them from certain types of liability for their users’ speech. It’s not one or the other; it’s both.

We’ve written numerous times about proposals in Congress to force platforms to be “neutral” in their moderation decisions. Besides being unworkable, such proposals are clearly unconstitutional: under the First Amendment, the government cannot force sites to display or promote speech they don’t want to display or remove speech they don’t want to remove.

It’s not hard to ascertain the motivations for Trump’s escalating war on Section 230. Even before he was elected, Trump was deeply focused on using the courts to punish companies for insults directed at him. He infamously promised in early 2016 to “open up our libel laws” to make it easier for him to legally bully journalists.

No matter your opinion of Section 230, we should all be alarmed that Trump considers a goofy nickname a security threat.

Trump’s attacks on Section 230 follow a familiar pattern: they always seem to follow a perceived slight by social media companies. The White House issued an executive order earlier this year that would draft the FCC to write regulations narrowing Section 230’s liability shield, though the FCC has no statutory authority to interpret Section 230. (Today, Congress is set to confirm Trump’s pick for a new FCC commissioner—one of the legal architects of the executive order.) That executive order came when Twitter and Facebook began to add fact checks to his dubious claims about mail-in voting.

But before, Trump never took the step of claiming that “national security” requires him to be able to use the courts to censor critics. That claim came on Thanksgiving, which also happened to be the day that Twitter users starting calling him “#DiaperDon” after he snapped at a reporter. Since then, he has frequently tied Section 230 to national security. The right to criticize people in power is one of the foundational rights on which our country is based. No matter your opinion of Section 230, we should all be alarmed that Trump considers a goofy nickname a security threat. Besides, repealing Section 230 would do nothing about the #DiaperDon tweets or any of the claims of mistreatment of conservatives on social media. Even if platforms have a clear political bias, Congress can't enact a law that overrides those platforms’ right to moderate user speech in accordance with that bias.

What would happen if Section 230 were repealed, as the president claims to want? Online platforms would become more restrictive overnight. Before allowing you to post online, a platform would need to gauge the level of legal risk that you and your speech bring on them—some voices would disappear from the Internet entirely. It’s shocking that politicians pushing for a more exclusionary Internet are doing so under the banner of free speech; it’s even more galling that the president has dubbed it a matter of national security.

Our free speech online is too important to be held as collateral in a routine authorization bill. Congress must reject President Trump’s misguided campaign against Section 230.