US President Donald Trump has been permanently suspended from Twitter, "due to the risk of further incitement of violence", the company says.
This means Twitter believes Mr Trump's tweets could encourage his supporters to plan protests and violent acts.
It comes after riots took place in Washington DC on Wednesday, which saw Mr Trump's supporters violently break into the US Capitol building to try to stop president-elect Joe Biden being certified as the next president. Four civilians and a police officer died.
Earlier this week, the president's Twitter, Facebook and Instagram accounts were blocked and YouTube deleted one of his videos. The popular gaming platform Twitch also placed an indefinite ban on the outgoing president's channel, which he has used for rally broadcasts. So has Snapchat.
Now, Twitter has decided to permanently ban him from their platform "after close review of recent Tweets from @realDonaldTrump account".
Why was Trump banned?
Some people have been calling for years on Twitter to ban Mr Trump altogether.
Former First Lady Michelle Obama tweeted on Thursday that social media companies should stop allowing Mr Trump's "monstrous behaviour" and permanently ban him.
Mr Trump was locked out of his Twitter account for 12 hours on Wednesday after he called the people who stormed the US Capitol "patriots"- which means someone who supports and defends their country.
Before Wednesday's violence, President Trump had told supporters on the National Mall in Washington that the election had been stolen. Hours later, as the violence mounted inside and outside the US Capitol, he appeared on video and repeated the false claim.
The march was partly organised online, and social media is a place where lots of fake news about the election are repeated. The companies that run the sites are under pressure to do more to moderate the content posted and have been unhappy with what Donald Trump says on previous occasions.
After being allowed back on Twitter, Mr Trump posted two tweets on Friday that the company said did not follow their rules and that they indicated the president does not plan to allow an 'orderly transition' of power and that he again implied that election fraud took place.
Twitter said: "In the context of horrific events this week, we made it clear on Wednesday that additional violations of the Twitter Rules would potentially result" in his account being removed from the platform.
350 Twitter employees also signed a letter which said that "despite our efforts to serve the public conversation, as Trump's megaphone, we helped fuel the deadly events of January 6th."
What happened next?
After Twitter had permanently suspended his @realDonaldTrump account, Mr Trump tweeted from the US president's official @Potus account suggesting he would "look at the possibilities of building out our own platform in the future" and said that "Twitter is not about FREE SPEECH."
But the tweets were removed from the platform as soon as they were posted.
It'll be a big blow to Mr Trump, as he used Twitter A LOT throughout his presidency.
He'd tweet pretty much all day every day to speak to supporters, fire officials, accuse the media of putting out "fake news" about him, and to talk about issues that have angered him - often using capital letters and lots of exclamation marks.
Whilst his critics said the president's account was a place of lies and misinformation, the platform allowed him to instantly connect with nearly 89 million followers.