X Corp (aka Twitter) may take legal action against one of its more outspoken critics. The Center for Countering Digital Hate (CCDH) says in a letter that X threatened a lawsuit against the anti-hate group on July 20th for allegedly making “false or misleading” claims against the social media giant and trying to scare advertisers. The Center published a research article in June asserting that X allowed explicitly racist and homophobic posts despite policies to the contrary, even days after they’d been reported.

X accused CCDH of using poor methodology, and not studying the 500 million posts on the service each day. It also maintained that the Center was taking funding from competitors or foreign governments as part of an “ulterior agenda,” according to The New York Times. CCDH rejects the allegations. It notes that it never claimed to be conducting a comprehensive study, and points to its documented methodology. It adds that X never said just what was inaccurate, and that it doesn’t accept any funding from companies or governments.

X has disbanded its communications team and isn’t available for comment. CCDH says it “will not be bullied” and will continue publishing its research. It also intends to post the original letter, and believes a lawsuit with “frivolous” claims could prove risky.

This is a developing story. Please check back for updates.