For years the company has prided itself on fostering open conversation, and creating a safe space for dialogue in its office, saying on its careers website that it is “all about flexibility and equity.” Employees on the anonymous forum for company reviews, Blind, ranked Twitter’s work-life balance 4.4 out of 5 stars, with several reviews of the company viewed by Fortune raving about the work life balance as one of the companies best aspects.

That could change significantly now that Elon Musk is taking over the company. 

Musk’s other companies, Tesla and SpaceX, are known for their demanding company cultures. Musk himself has previously been accused of flying into unpredictable rages with employees and exploding at his managers. A female engineer at SpaceX previously accused the company of having a sexist culture in a public essay. 

In one instance, Musk berated a group of employees working on the company’s Model 3 sedan assembly line, saying their work was “complete shit,” demanding the engineers state “who the f— you are and what the f— you’re doing to fix my goddamn line,” according to the book Power Play: Tesla, Elon Musk, and the Bet of the Century, Business Insider reported. One of the employees reportedly quit on the spot. Musk has disputed some of the anecdotes in the book.

Musk has also been accused of firing those he disagrees with. In 2006, when his then-head of marketing, Jessica Switzer, spent money he thought unnecessary ahead of Tesla’s first Roadster reveal party, he had her and a public relations firm let go, according to the book.

Musk said in a press release announcing his Twitter takeover that he wants to make the company’s algorithms open-source, authenticate all humans, and battle spambots that are widespread on the platform. He also wants to emphasize free speech on the platform, he wrote in the press release, which has some employees worried about the potential ramifications for Twitter’s operations.

One employee, Edward Perez, a director of product management for Twitter’s societal health team, said in a Monday afternoon tweet that he and his coworkers are feeling “genuine discomfort and uncertainty.”

“Most of us believe deeply that Twitter is much more than a tech platform; we have a deep responsibility to society. I hope our new owner gets that,” Perez said in the tweet.

A survey of 170 employees at Twitter from Blind found that 51% were worried about Musk acquiring Twitter, Fortune previously reported.  

Whereas Twitter boasts 3.9 out of 5 stars overall on the platform, Tesla and SpaceX rank lower. Both Musk-owned companies received less than 3 out of 5 stars for work-life balance—Tesla had a score of 2.5; SpaceX a 2.1—and several users reported that the company demands a lot of their attention.

One anonymous Blind user who said they were a current employee at Tesla said the cons of working there are that “your family will miss you and you will feel the effects of stress resulting from crazy schedules.”

Musk has characterized himself as a nanomanager, describing himself as more detail-oriented and controlling than a micromanager, in a 2015 interview with the Wall Street Journal. “I have OCD on product-related issues,” he told the Journal. “I always see what’s…wrong. Would you want that? When I see a car or a rocket or spacecraft, I only see what’s wrong. I never see what’s right. It’s not a recipe for happiness.”