Elon Musk is making good on a legal threat and suing a UK-based nonprofit that’s criticized Twitter’s approach to stopping hate speech on the social media platform.

In a bit of irony, Twitter — also known as X— says it’s fighting for free speech by suing the nonprofit, the Center for Countering Digital Hate (CCDH), after it published a report arguing that the company is failing to crack down on racist, homophobic, and antisemitic tweets.

The CCDH is using shady practices and flawed research methodologies to drive advertisers away from Twitter, the company alleges in a blog post.

“X is a free public service funded largely by advertisers. Through the CCDH's scare campaign and its ongoing pressure on brands to prevent the public’s access to free expression, the CCDH is actively working to prevent public dialogue,” Twitter claims. (Earlier this month, Musk conceded Twitter continues to bleed cash due to a 50% drop in advertising revenue.)

The lawsuit, filed on Monday, goes on to claim the CCDH is an activist organization masquerading as a research group. The document also alleges the CCDH “unlawfully” scraped tweets from Twitter and misused a third-party service called Brandwatch to make “unsubstantiated and incorrect assertions about the presence of hate speech on X.”

The lawsuit speculates that the CCDH could be receiving funds from foreign governments, without supplying any evidence. In a tweet on Monday, Musk reiterated the foreign interference claim about the CCDH, later adding: “Their actual goals have nothing to do with hate speech and everything to do with censorship of public dialogue.”

The lawsuit is suing the nonprofit for breach of contract, violation of the Computer Fraud and Abuse Act, along with interference in contractual relations, and is demanding damages.

However, the CCDH says the lawsuit shows Musk wants to silence the truth about hate speech on Twitter without addressing the problem. “Elon Musk’s latest legal threat is straight out of the authoritarian playbook —he is now showing he will stop at nothing to silence anyone who criticizes him for his own decisions and actions,” the group says.

"CCDH Inc does not accept any funding from social media companies or government bodies, both of whom we praise or criticize without fear or favor. As a US 501(c)(3) public charity, we comply with all rules regarding disclosure of our financial information, including donors.”

The CCDH also says “people don’t want to see or be associated with hate, antisemitism, and the dangerous content that we all see proliferating on X.” Hence, Musk is trying to “shoot the messenger” by attacking the nonprofit.

But in its blog post, Twitter maintains that “more than 99.99% of post impressions are healthy” since the social media platform has been restricting the reach of tweets containing hate speech and other rule-breaking content.