Updated

Twitter and several other social media giants defeated a lawsuit by right-wing activist Laura Loomer and the conservative group Freedom Watch in the D.C. Circuit Court of Appeals on Wednesday, in a case that highlighted Republican frustrations with what they perceive as pervasive online censorship -- and the challenges they face in doing something about it.

The decision came as President Trump vowed to take action to combat what he called Twitter's attempts to "interfere" in the 2020 election by suppressing his posts under the guise of a neutral "fact-checking" operation.

Fox News reported on Wednesday that the head of Twitter's fact-checking division has repeatedly mocked Trump and his supporters; Twitter responded by calling the reporting accurate but "unfortunate."

TWITTER EXEC OVERSEEING FACT CHECK EFFORT HAS HISTORY OF ANTI-TRUMP TWEETS

The appellate court held that the civil complaint by Loomer and Freedom Watch failed to state a First Amendment violation because Twitter, Apple, Facebook and Google are not "governmental actors." The First Amendment only prohibits government suppression of speech, the court noted, and Supreme Court precedent makes it clear that "a private entity who provides a forum for speech is not transformed by that fact alone into a state actor."

Additionally, the complaint's Sherman Antitrust Act claim failed to show an "unlawful conspiracy," even if the factual allegations were all assumed to be true for the purposes of a motion to dismiss, the appellate court ruled. While Loomer and Freedom Watch alleged that the tech giants acted in parallel to suppress conservative views and shared left-wing political opinions, the complaint did not show that the companies acted in coordination.

"Freedom Watch puts forth two additional factors that it claims suggest conspiracy: that the Platforms are pursuing a revenue-losing strategy and that they are motivated by political goals," the court wrote. "But Freedom Watch does not explain why either factor tends to show an unlawful conspiracy, rather than lawful independent action by the different Platforms."

The plaintiffs also attempted to bring a claim under D.C. law, which prohibits politically based discrimination. But, contrary to the interpretation advanced by the city in an amicus brief and the plaintiffs in their complaint, the appellate court held that the law only applies to businesses that operate out of a particular location in D.C., as opposed to businesses that simply conduct incidental business in the city.

TWITTER PUTS WARNING LABEL ON TRUMP TWEET ON MAIL-IN BALLOTS, DESPITE EXPERTS BACKING UP HIS CONCERNS

Although the lawsuit was defeated, complaints from conservatives are likely to continue. In a post retweeted by the Trump campaign, The Daily Caller's Logan Hall noted Tuesday that Twitter has not appended a warning label on tweets from Chinese government representatives engaging in a propaganda campaign to blame the U.S. for the spread of coronavirus. "The deeper problem: many of the big tech companies that people hold near and dear to their hearts have no actual allegiance to America or American values," Hall wrote.

Others observed that Twitter had not fact-checked a false claim on police shooting statistics that was shared by New York Democrat Rep. Alexandria Ocasio-Cortez.

Twitter CEO Jack Dorsey testifies before the House Energy and Commerce Committee hearing on Twitter's algorithms and content monitoring on Capitol Hill in Washington, U.S., September 5, 2018. REUTERS/Chris Wattie - RC1D5C3E3B60

Twitter CEO Jack Dorsey testifies before the House Energy and Commerce Committee hearing on Twitter's algorithms and content monitoring on Capitol Hill in Washington, U.S., September 5, 2018. REUTERS/Chris Wattie - RC1D5C3E3B60 (Reuters)

And just two months ago, the Trump campaign essentially declared war when Twitter flagged a video uploaded by the campaign as "manipulated media," only to rebuff the campaign's efforts to have the platform flag a similar video uploaded by the Biden team.

Earlier Wednesday, President Trump warned social media giants that the federal government could “strongly regulate” or “close them down” if they continue to “silence conservative voices,” amid a flaring battle with Twitter after the platform fact-checked one of his tweets for the first time.

Twitter's warning label was placed on Trump's tweets concerning the fraud risks of nationwide mail-in voting ballots, even though a Twitter spokesperson acknowledged to Fox News that Trump's tweet had not broken any of the platform's rules, and despite the fact that several experts have called mail-in balloting an invitation to widespread fraud.

Indeed, bipartisan panels of experts, as well as journalists, have found that absentee balloting increases the risk of voter fraud.

"Absentee ballots remain the largest source of potential voter fraud," read the conclusion of a bipartisan 2005 report authored by the Commission on Federal Election Reform, which was chaired by former President Jimmy Carter and former Secretary of State James Baker.

"Twitter 'fact-checkers' really suck," wrote Dan Bongino, a Fox News contributor. He linked to a 2012 article in The New York Times headlined, "Error and Fraud at Issue as Absentee Voting Rises." The article states that "votes cast by mail are less likely to be counted, more likely to be compromised and more likely to be contested than those cast in a voting booth, statistics show."

Fox News later reported that Twitter's head of fact-checking, Yael Roth, has previously referred to Trump and his team as "ACTUAL NAZIS," mocked Trump supporters by saying that "we fly over those states that voted for a racist tangerine for a reason," and called Senate Majority Leader Mitch McConnell, R-Ky., a "personality-free bag of farts." Last August, Twitter suspended McConnell's Twitter account, prompting the GOP to threaten to cut off advertising on the site until Twitter relented.

Twitter thread Tuesday by White House press secretary Kayleigh McEnany highlighted numerous recent stories documenting fraud concerns over mail-in ballots across the country, including a Fox News piece. And, experts have said that a "genuine absentee ballot fraud scandal" is currently underway in a New Jersey city council election.

“Republicans feel that Social Media Platforms totally silence conservatives voices,” Trump tweeted. “We will strongly regulate, or close them down, before we can ever allow this to happen. We saw what they attempted to do, and failed, in 2016. We can’t let a more sophisticated version of that happen again.”

The president added: “Just like we can’t let large scale Mail-In Ballots take root in our Country. It would be a free for all on cheating, forgery and the theft of Ballots. Whoever cheated the most would win. Likewise, Social Media. Clean up your act, NOW!!!!”

It was unclear what mechanism Trump was referring to, although the Justice Department (DOJ) has begun an antitrust review of big tech giants, and conservative lawmakers have floated other options. Late Tuesday, Sen. Marco Rubio, R-Fla, noted on Twitter that Twitter could soon lose some of its legal protections.

That was a reference to Section 230 of the Communications Decency Act, which broadly protects online content platforms from liability. For example, a defamatory comment posted by a Twitter user would not ordinarily lead to liability for Twitter, even if the platform allows the defamatory content to remain online after becoming aware of it.

"The law still protects social media companies like @Twitter because they are considered forums not publishers," Rubio wrote. "But if they have now decided to exercise an editorial role like a publisher then they should no longer be shielded from liability & treated as publishers under the law."

Sen. Josh Hawley, R-Missouri, meanwhile, wrote a letter to Twitter's CEO seeking the "sources on which Twitter relied to decide to editorialize regarding the President's political speach," and an explanation as to "why you think that companies that act like publishers should not be treated like publishers."

"Twitter's decision to affix its own editorial content to users' posts brings into question the basis" for its immunity, Hawley said.

He argued it was "alarming" that Twitter had singled out Trump, while not fact-checking Chinese propaganda posts -- or any other post on the website, for that matter.