Andy Pincus Mayer Brown's Andrew Pincus, speaking at the 18th Annual Legal Reform Summit, held at the U.S. Chamber of Commerce in Washington. Photo: Diego M. Radzinschi/ ALM.

The Center for Democracy and Technology has sued President Donald Trump over an executive order seeking to crack down on social media companies' "selective censorship" after Twitter flagged one of the president's posts as potentially misleading.

Mayer Brown is representing the Washington, D.C.-based tech policy nonprofit in one of the first legal challenges to the executive order delegating several agencies to review Section 230, a provision within the Communications Decency Act shielding online companies from liability for user-generated content. 

The complaint, filed Tuesday in the U.S. District Court for the District of Columbia, alleges that the order violates the free speech protections of social media companies and its users, and seeks a preliminary and permanent injunction enjoining the Trump administration from enforcing the order. 

The center's incoming general counsel, Avery Gardiner, who filed the complaint alongside a Mayer Brown team led by Andrew Pincus in Washington, D.C., said, "The main goal of the suit is to defend basic First Amendment freedoms for all of us. What this executive order does is threaten all of our rights to speak freely online."

Gardiner said she expects to see more challenges from public interest-oriented groups across the political spectrum, as well as some companies pushing back against the restrictions.

The order came shortly after Twitter fact-checked a post from the president claiming that mail-in ballots would lead to voter fraud.

Gardiner said that in these "incredibly difficult times," referring to the national protests over the death of George Floyd, the group worries about any online affront to free speech, but that the president threatening the ability of social media platforms to moderate speech about elections is "mind-blowingly terrifying and needs to stop." 

"It's not just about what he's trying to do against Twitter," she said. "He is not just sending a shot across the bow, but a shot into the hull of any online platform that accepts user-generated content."

The order enlists the U.S. attorney general to form a working group of state attorneys general to review current state statutes that could enforce prohibitions on online content moderation and propose federal legislation. The presidential action also seeks to begin a Federal Communications Commission rulemaking process to propose regulations clarifying Section 230. Both procedures would likely not have an immediate effect on online free speech. 

"The order says very, very loudly that if you speak in ways that I don't like, I will find a way to make your life painful, and that's a very damaging message, even if some of the specific effects of the order don't come into effect for a period of time," she said.

A White House representative did not respond to a request for comment Tuesday afternoon. 

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