Less than 24 hours after Elon Musk endorsed an antisemitic post on X as “the actual truth” of what Jewish people were doing, IBM paused its advertising on the social media platform as X’s CEO, Linda Yaccarino, and others at the company scrambled Thursday to contain the fallout.

X employees said Thursday that they had gotten calls from advertisers wondering why Musk was making comments seen as antisemitic and why their ads were showing up next to white nationalist and Nazi content, according to internal messages that were viewed by The New York Times. IBM cut off about $1 million in advertising spending that it had committed to the platform for the last three months of the year, the messages said.

In a note to employees Thursday morning, Yaccarino said that “X is a platform for everyone” and that “discrimination by everyone should STOP across the board.” She said the company had been clear about its work to fight antisemitism and discrimination, and later shared a similar message on X.

In a statement, IBM said it “has zero tolerance for hate speech and discrimination and we have immediately suspended all advertising on X while we investigate this entirely unacceptable situation.”

X did not respond to a request for comment. The Financial Times earlier reported on IBM’s pause in advertising on X.

Musk, who bought Twitter last year and renamed it X, has faced increasing criticism that he has tolerated and even encouraged antisemitic abuse on his social media platform. He has attacked George Soros, a financier who is a frequent target of antisemitic abuse, and threatened to sue the Anti-Defamation League, a rights group that has highlighted the rise in antisemitism on X.

On Wednesday, Musk went further when he agreed with a post from an X account accusing Jewish communities of pushing “hatred against whites that they claim to want people to stop using against them.” Jewish people are now “coming to the disturbing realization that those hordes of minorities that support flooding their country don’t exactly like them too much,” the account added.

“You have said the actual truth,” Musk replied to the post.

Jewish groups have compared the statement that Musk endorsed to the “Great Replacement Theory,” the far-right idea that minorities are replacing white European populations.

“It is the deadliest antisemitic conspiracy theory in modern U.S. history,” the American Jewish Committee, a U.S.-based Israel advocacy group, wrote on X on Thursday. “To amplify it on @X is incredibly dangerous.”

Social media platforms, in general, have faced rising scrutiny since Hamas attacked Israel on Oct. 7 and Israel retaliated. Antisemitic and Islamophobic hate speech has surged across the sites and has been especially prominent on X, according to the Anti-Defamation League and researchers. On Wednesday night, more than a dozen Jewish creators and celebrities also confronted TikTok executives in a private meeting, urging them to do more to address a rise in antisemitism and harassment on the video service.

In September, Musk met with Israeli Prime Minister Benjamin Netanyahu at a Tesla factory in the San Francisco Bay Area after facing accusations of antisemitism.

“It’s not an easy thing to be maligned — I know you’ve never seen that, right?” Netanyahu asked Musk at one point.

“Me, maligned?” Musk said, laughing. “Never.”

At X, Yaccarino has previously intervened in situations involving antisemitic content on the platform. This month, a sales employee flagged apparent antisemitic posts that the site had not removed, leading Yaccarino to ask that the posts be reviewed, two people with knowledge of the situation said. The employee who flagged the posts is no longer with the company, the people said. The Information earlier reported Yaccarino’s actions on those posts.

On Thursday morning, X sales employees asked about Musk’s posts and what they could relay to their clients, according to messages seen by The New York Times. They also cited an article from Media Matters for America, a left-wing advocacy group, which showed that ads from major brands were appearing on X next to posts promoting white nationalist and Nazi perspectives.

“A lot of large advertisers have been called out in this article,” one employee wrote.

Another employee wrote that she was concerned because she worked with Apple, a major advertiser that was mentioned in the Media Matters piece, and asked if some of the posts “were manipulated.” An employee responded that the company’s trust and safety team, which has experienced layoffs and resignations, was “actively looking into this.”