CNN Business  — 

Wednesday’s assault on the US Capitol by President Donald Trump’s supporters has created a crisis moment for the tech companies that have given him a free platform to incite violence and spread debunked claims of election fraud to his fervent supporters.

After hours of silence while their sites were swarmed with images of rioters breaking Capitol windows and threatening law enforcement, tech platforms including Facebook (FB), Twitter (TWTR) and YouTube were forced to take increasingly aggressive steps to limit Trump’s online accounts.

First the platforms tried labeling Trump’s posts, including his claim that Vice President Mike Pence lacked the “courage” to do what was necessary to ensure Trump remains in the Oval Office. Twitter moved to restrict replies, likes and retweets of that tweet.

When that didn’t seem to stem Trump’s encouragement of his supporters, they blocked some of Trump’s content, such as a video he recorded expressing sympathy for the rioters. Facebook’s vice president of integrity, Guy Rosen, said the decision was made because “on balance we believe [the video] contributes to rather than diminishes the risk of ongoing violence.” YouTube said the video was removed for violating company policies against sowing doubt about the 2020 elections.

But it wasn’t until late in the day that Twitter finally took the unprecedented step of locking Trump’s account, albeit temporarily. Twitter hid three of Trump’s tweets behind labels and said he would be prevented from tweeting for at least 12 hours after he voluntarily deleted the tweets. Further violations, Twitter warned, would result in a permanent suspension. No sitting president has ever been banned from Twitter.

It was a significant escalation in the tense relationship between Trump and the social media platforms he has leveraged to provoke his base.

On Thursday, Facebook took it further. In a blog post, CEO Mark Zuckerberg said the company would ban Trump’s account from posting for at least the remainder of his term in office and perhaps “indefinitely.”

That move came after a late Wednesday flood of calls by civil rights leaders and other critics to ban Trump outright.

The Anti-Defamation League issued a statement calling for Trump’s permanent suspension from social media and accusing Trump of promoting sedition and inciting violence.

“President Trump has a responsibility to call for an end to this violence and unrest that he has sowed. His campaign of disinformation is a clear and present danger to our democracy,” said ADL CEO Jonathan Greenblatt. “But until such time as that happens, social media companies should suspend his accounts ASAP as they would do for anyone else advocating disinformation and promoting violence. It’s time.”

Jessica Gonzalez, co-CEO of Free Press, an advocacy group, tweeted that the major platforms, including Facebook, Twitter, YouTube and TikTok, face “another inflection point here.”

“Hey Mark Zuckerberg, @jack, @SusanWojcicki and @sundarpichai – Donald Trump just incited a violent attack on American democracy. Is that FINALLY enough for you to act?!”

The NAACP, the actor Sacha Baron Cohen and countless others echoed the call.

The pressure on tech companies to de-platform Trump has now reached its zenith, coinciding with his attempts to overturn the certified results of an election that made him a one-term president.

But the calm may be short-lived. Trump’s posting privileges on Facebook could well be restored once the two weeks are up. And because Trump complied with Twitter’s requirement that he delete three violative tweets in order to restore his account access, he should be able to start tweeting on Thursday if he wants.