X owner Elon Musk said on Saturday that he would be filing a lawsuit against leftist outlet Media Matters for America over a story it ran this week that he said was misleading and intended to undermine free speech.

Musk announced the suit early Saturday morning, promising to file the suit as soon as the courts opened on Monday. The Media Matters story at the center of the suit was published on Thursday and claimed that X was placing ads for major corporations alongside Nazi-related content.

In the aftermath of the story, multiple corporations said that they would be pulling advertising from X, including Apple and IBM.

“The split second court opens on Monday, X Corp will be filing a thermonuclear lawsuit against Media Matters and ALL those who colluded in this fraudulent attack on our company,” Musk said, indicating that the suit would target the board and their “network of dark money.”

A press release from Musk said that the Media Matters story “completely misrepresented the real user experience on X, in another attempt to undermine freedom of speech and mislead advertisers.”

Musk said that X was committed to free speech on the platform, even objectionable speech, and that people had the right to decide what to read or watch.

“Despite our clear and consistent position, X has seen a number of attacks from activist groups like Media Matters and legacy media outlets who seek to undermine freedom of expression on our platform because they perceive it as a threat to their ideological narrative and those of their financial supporters,” the release said.

Musk said that Media Matters created a “contrived” experience by using an alternate account to curate what posts appeared on the timeline. “Once they curated their feed, they repeatedly refreshed their timelines to find a rare instance of ads serving next the content they chose to follow,” Musk said.

He said that X logs indicated that of the 5.5 billion ad impressions the day Media Matters pulled its research from, that less than 50 were served alongside the content highlighted by Media Matters.

For one “brand showcased in the article, two of its ads served adjacent to 2 posts, 3 times, and that ad was only seen in that setting by one user, the author of the Media Matters article,” Musk said.

In addition to Apple and IBM, Disney, Warner Bros. Discovery, Comcast/NBCUniversal, Lionsgate and Paramount Global all announced they were pausing ads on the social media platform.