Trump threatens to 'strongly regulate' social media platforms after Twitter labels his tweets

U.S. President Donald Trump on Wednesday threatened to "strongly regulate" or even shut down social media platforms after Twitter applied a fact-check to two of his tweets this week.

Trump did not elaborate on what actions he could take. But the threat is Trump's clearest expression of intent to use the power of government to target his perceived political enemies in the private sector -- businesses that already enjoy wide latitude under the law to moderate their platforms as they see fit. And it raises the stakes for Twitter and Facebook as they grapple with Trump's misleading claims about mail-in voting and his baseless insinuations that a cable TV news host was involved with an aide's murder decades ago.

"Republicans feel that Social Media Platforms totally silence conservatives voices. We will strongly regulate, or close them down, before we can ever allow this to happen," Trump tweeted Wednesday. He went on to accuse the tech industry of trying to interfere in the 2016 election, before repeating an unfounded claim about voter fraud stemming from mail-in ballots.

"We can't let large scale Mail-In Ballots take root in our Country," Trump tweeted. "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!!!!"

Conservatives have long complained that tech platforms algorithmically censor right-wing voices. The claims derive from a perception that Silicon Valley's largely left-leaning workforce has designed social media products to discriminate against conservatives, though the companies strongly deny the allegations.

Some executives, like Facebook CEO Mark Zuckerberg, have sought to accommodate conservative voices by meeting with them privately, and even meeting with Trump himself.

Facebook and Twitter didn't immediately respond to requests for comment Wednesday.

Trump's Twitter outburst followed an unprecedented decision by Twitter on Tuesday evening to apply a fact-checking label to Trump's content for the first time.

The label, which Twitter has designed to combat misinformation and unverified claims, linked to a curated page with links and summaries of articles describing how Trump's claims on mail-in ballots are unfounded.

Shortly after the labels were applied, Trump took to Twitter to claim the company "is interfering in the 2020 Presidential Election" and "stifling FREE SPEECH." He added that he "will not allow it to happen!"

Privately, officials from the Federal Trade Commission and Federal Communications Commission have expressed concerns about a prior proposal from the White House to appoint those agencies as direct regulators of political content on social media.

Meanwhile, major tech industry players remain under federal and state antitrust investigation. But antitrust probes tend to be highly technical and are usually limited to the impact of corporate conduct on competition in the marketplace.