“Twitter has had a massive drop in revenue, due to activist groups pressuring advertisers, even though nothing has changed with content moderation and we did everything we could to appease the activists,” he wrote. “Extremely messed up! They’re trying to destroy free speech in America.”

The outburst comes on the same day that Twitter is cutting its workforce nearly in half under Musk rule, and as advertising firms have become wary of Twitter of late, in part because of a dramatic rise in hate speech and conspiracy theories appearing in people’s timelines.

The Anti-Defamation League said it found over 1,200 tweets and retweets with anti-Semitic memes on Twitter in a roughly 24-hour period after Musk took over the company. Instances of the N-word jumped by 500% in the 12 hours after he took over the platform. Twitter blamed the rise on a “trolling campaign,” saying more than 50,000 tweets repeatedly using “a particular slur” had come from just 300 accounts.

IPG, which is one of the world’s largest advertising companies, has recommended its clients pause spending on Twitter, due to moderation concerns. The company’s clients include Walmart, American Express, Coca-Cola, Fitbit, GoPro, Johnson & Johnson, Levi Strauss & Co, Mattel and Spotify. It manages roughly $40 billion in marketing campaigns worldwide.

An IPG representative told the New York Times its clients were planning to pause spending on Twitter until they had more clarity on (and confidence in) the social media site’s direction.

Musk’s post, though, more likely is targeted at the more than 40 civil rights groups that sent an open letter to Twitter’s 20 top advertisers earlier this week, which read, in part, “If Elon Musk follows through with just a fraction of what he has already committed to doing, then Twitter will not and can not be a safe platform for brands.”

The added drama comes as Twitter intends to start cutting staff Friday. The company announced the move in an email to employees late Thursday. Musk is expected to get rid of half the workforce, making good on plans to slash costs at the platform he acquired for $44 billion last month. The anticipated layoffs have already resulted in a class-action lawsuit, saying the Worker Adjustment and Retraining Notification Act prohibits Twitter from making mass layoffs without at least 60 days of advance notice.

Musk has also posted particularly controversial tweets in the lead up to his Twitter acquisition, and after he took over.

Just days after the deal closed, Musk tweeted a baseless and salacious conspiracy theory about a recent attack on Paul Pelosi, husband of Democratic Speaker of the House Nancy Pelosi.

“There is a tiny possibility there might be more to this story than meets the eye,” Musk wrote. He later deleted the tweet.

In mid October, he posted, then deleted, a meme of himself and Kanye West, now known as Ye, after the rapper said he would buy Parler, a right-wing social media platform. He wrote under the meme, “Fun times ahead.” He also posted a meme of himself, Ye, and former President Donald Trump portrayed as the Three Musketeers, each in charge of a social media platform.