Matt Taibbi, a journalist who writes for “Twitter Files,” reluctantly declared on Friday that he would be departing from the social media platform due to recent changes made by CEO Elon Musk, which have rendered it “unusable” for him.

Last year, Taibbi was among a select group of journalists granted access to Twitter’s internal communications by Musk after he acquired the social media platform. This access revealed how the company collaborated with government agencies to censor and suppress information and news, including the New York Post’s Hunter Biden laptop scoop in the lead-up to the 2020 election.

As a condition of his internal access, Taibbi agreed to share his reporting live via extended Twitter threads. However, Taibbi and fellow reporter Bari Weiss posted their reports on Substack, a platform that enables writers to share their stories with paying subscribers, Mediaite reported.

Following the introduction of Notes, a new feature on Substack that allows for short-form posts comparable to a tweet, Twitter reportedly reacted by prohibiting the sharing of links or even embedding tweets in Substack posts.

In a piece titled “The Craziest Friday Ever,” Taibbi explained why he was leaving Twitter and stated that Musk’s platform views Substack Notes as “a hostile rival.”

He said that the move will likely “come with a price as far as any future Twitter Files reports are concerned.”

“Earlier this afternoon, I learned Substack links were being blocked on Twitter. Since being able to share my articles is a primary reason I use Twitter, I was alarmed and asked what was going on,” Taibbi tweeted.

“It turns out Twitter is upset about the new Substack Notes feature, which they see as a hostile rival. When I asked how I was supposed to market my work, I was given the option of posting my articles on Twitter instead of Substack,” the former Rolling Stone journalist continued.

“Not much suspense there; I’m staying at Substack. You’ve all been great to me, as has the management of this company. Beginning early next week I’ll be using the new Substack Notes feature (to which you’ll all have access) instead of Twitter, a decision that apparently will come with a price as far as any future Twitter Files reports are concerned,” Taibbi wrote.

“It was absolutely worth it and I’ll always be grateful to those who gave me the chance to work on that story, but man is this a crazy planet,” he concluded.

In December 2022, Taibbi released the initial of several reports on “Twitter Files,” which exposed the chaos and disorder behind closed doors after a small group of top-level executives decided to label The New York Post’s Hunter Biden story as “hacked material” without any proof. According to Taibbi, the decision to censor the Post’s story was made “at the highest levels of the company,” but without then-CEO Jack Dorsey’s involvement. Emails and comments from former Twitter employees reviewed by the journalist demonstrated that “everyone knew” the social media giant’s suppression of the story “was f–ked.”

During a congressional hearing on misinformation and social media in March 2021, while still CEO, Dorsey acknowledged that blocking The Post’s report was a “total mistake.”

Fellow reporter Bari Weiss published the second set of Twitter Files in a thread just a few days later, revealing how the social media company “shadow-banned” several far-right users without their knowledge.

Taibbi then reported on how Twitter decided to ban former President Donald Trump from the platform after the Capitol riot on Jan. 6, 2021, while high-ranking officials kept in touch with numerous government agencies about the decision.

It was later discovered that despite the company’s monitors finding no violations in the former President Trump’s tweets, staffers and top executives at Twitter pushed for his removal from the site.

In another explosive report, Taibbi exposed the involvement of the CIA in Twitter’s content moderation for years. Internal communications revealed that FBI’s Elvis Chan, who was featured in previous “Twitter Files” releases, requested company executives to “invite an OGA” (Other Government Agency, typically referring to the CIA) to an upcoming conference.

Taibbi stated that “regular meetings of the multi-agency Foreign Influence Task Force (FITF)” – attended by Twitter and “virtually every major tech firm including Facebook, Microsoft, Verizon, Reddit, even Pinterest, and many others” – had “FBI personnel, and – almost always – one or two attendees marked ‘OGA'” to discuss foreign matters.

The documents reveal that through the FITF, US intelligence tasked Twitter analysts with conducting extensive investigations into domestic Twitter accounts alleged to have suspicious foreign connections. These efforts intensified in the run-up to the 2020 presidential election but continued through 2022.

Twitter content monitors analyzed users’ IP data, phone numbers and even weighed whether user names were “Russian-sounding” to confirm the government’s accusations — but often failed to do so.

Taibbi testified before the House Judiciary Committee last month and accused the mainstream media of being “an arm of a state-sponsored thought-policing system,” creating “a form of Digital McCarthyism.”

“We learned Twitter, Facebook, Google and other companies developed a formal system for taking in moderation ‘requests’ from every corner of government: the FBI, DHS, HHS, DOD, the Global Engagement Center at State, even the CIA,” he said.

The same day he testified, an IRS agent visited to Taibbi’s home in New Jersey. 

Taibbi said the agent who visited left a note instructing him to call the tax bureau four days later. When he did, an IRS agent reportedly told him that his returns for 2018 and 2021 had been rejected due to identity theft concerns.

According to reports, Taibbi provided documents to the House Judiciary Committee indicating that his 2018 tax return was accepted electronically, and he claimed that the recent rejection notice he received in March was the first time in over four years that he was informed of its rejection.

House Judiciary Committee Chairman Jim Jordan (R-Ohio) demanded Monday that the IRS hand over all documents relating to the visit by April 10, including “[a]ll documents and communications between or among the IRS, Treasury Department, and any other Executive Branch entity referring or relating to Matthew Taibbi.”

It’s unclear if Taibbi will continue to publish “Twitter Files” reports after his departure from the platform, where he has 1.8 million followers.