Owner of Twitter Inc. Elon Musk, who calls himself a “freedom of speech absolutist,” resorted to firing company engineers who publicly contradicted his tweets on social media, writes Bloomberg.

In one case, Musk announced his resignation on Twitter. In another, a former employee said he was fired after openly reprimanding Musk.

Eric Frohnhoefer, an engineer who worked on Twitter’s app for the Android mobile operating system, on Sunday reposted one of Musk’s tweets with a comment, saying that Musk’s understanding of a technical part of Twitter’s app was “wrong.” Musk replied and asked Frohnhoefer to elaborate, before writing, “Twitter is super slow on Android. What have you done to fix that?”

After trying to explain his reasoning in a series of tweets, another user asked Fronhoefer why he didn’t share his feedback with his new boss privately. The engineer, who has worked at Twitter for more than eight years, replied: “maybe he should ask questions privately. Maybe use Slack or email.”

On Monday morning, Musk wrote that Frohnhoefer had been fired. Frohnhoefer retweeted the post and included the saluting emoji that many employees used when they were fired earlier this month. Twitter and Fronhoefer did not immediately respond to requests for comment on his status.

Another engineer, Ben Leib, was also fired after contradicting Musk. He retweeted Elon’s same tech post, writing: “As the former tech lead for timelines infrastructure at Twitter, I can confidently say this man has no idea wtf he’s talking about.” Leib, who worked at Twitter for ten years, confirmed to Bloomberg that he was fired on Sunday.

Twitter has been thrown into chaos since Musk took over as CEO late last month. Many workers remain upset that Musk fired half of the company’s more than 7,000 employees, including most top executives, about a week after the $44 billion deal closed.

The billionaire also quickly changed the corporate culture. While it wasn’t previously common for employees to publicly challenge management on Twitter, employees often spoke out in internal Slack channels and via email, sometimes posting company-wide criticisms or concerns. According to current and former employees, Musk’s changes led to a lack of internal communication about who was in charge and what the company’s priorities were.

The moves have also led to concerns that Twitter has become vulnerable to technical glitches. On Monday, the company implemented another code freeze, halting feature updates to the app, with no clear reason given to employees.