Four Twitter employees raised concerns about Elon Musk’s ability to influence the company’s policies on abusive users and harmful content.

Elon Musk recently bought a 9.1 percent stake in Twitter. This means the billionaire is now the largest shareholder of the social media platform. He has been invited to join the company’s board of directors.

For Twitter employees, who wish to remain anonymous, Musk’s position on moderation could weaken Twitter’s efforts to moderate content. They also believe that his view could allow trolling and mob attacks to gain ground.

To bolster their case, the staffers point to Musk’s history of using Twitter to attack critics.

Despite Twitter’s statement that the board does not make policy decisions, some employees expressed doubts about the company’s commitment to such a statement.

Employees believe Musk’s involvement could in the long run affect Twitter’s corporate culture. The billionaire has been heavily criticized for posting memes mocking transgender people, efforts to reduce the spread of COVID-19.

Some employees are now looking for jobs elsewhere, having openly expressed their position not to work with Musk.