X is preventing users from posting links to a newsletter containing a hacked document that’s alleged to be the Trump campaign’s research into vice presidential candidate JD Vance. The journalist who wrote the newsletter, Ken Klippenstein, has been suspended from the platform. Searches for posts containing a link to the newsletter turn up nothing.

The document allegedly comes from an Iranian hack of the Trump campaign. Though other news outlets have received information from the hack, they declined to publish. Klippenstein says in his newsletter that a source called “Robert,” with an AOL email address, offered him the document. Contained in it are what appear to be Vance’s full name, addresses, and part of his social security number.

X said in a post on its safety account that Klippenstein was “temporarily suspended for violating our rules on posting unredacted private personal information.” The company didn’t comment on why links to Klippenstein’s article are blocked. The X account for Klippenstein’s newsletter confirmed the reasoning for the ban. “Ken Klippenstein has been banned by Twitter for publishing private information in contradiction of its rules,” wrote KlipNews.

Twitter, before it was bought by Elon Musk, had a policy regarding hacked materials — but the page is no longer available. A pre-Musk version of the policy, dated 2019, stated that posting or linking to hacked content is prohibited. Under this policy, links to a story by The New York Post about Hunter Biden, the current president’s son, were banned. But in October 2020, Twitter changed its policy to say that it would no longer block hacked materials, after an outcry about how the company had handled the Post story. “Straight blocking of URLs was wrong, and we updated our policy and enforcement to fix,” wrote then-CEO Jack Dorsey.

Musk was one of the people who was unhappy with the decision to ban links to the Post’s story. “Suspending the Twitter account of a major news organization for publishing a truthful story was obviously incredibly inappropriate,” Musk wrote of the decision on the story in April 2022. He even invited former Rolling Stone pundit Matt Taibbi to examine internal documents showing how Twitter handled the decision. (In the course of tweeting his conclusions, Taibbi exposed the email addresses of Dorsey and Representative Ro Khanna.)

It is unclear why X is blocking Klippenstein’s story, but attempts by three staffers at The Verge to post links of Klippenstein’s newsletter failed. We received error messages that read, “We can’t complete this request because this link has been identified by X or our partners as being potentially harmful. Visit our help center to learn more.”

Update, September 26th: Added comment from X’s safety account.