SpaceX, the rocket ship company run by Tesla CEO Elon Musk, has fired several employees involved in an open letter that blasted the colorful billionaire for his behavior, according to media reports.The reports published Friday, June 17,  cited an email from Gwynne Shotwell, SpaceX’s president, saying the company had terminated employees who put together and circulated the letter. The letter writers denounced Musk for actions that they said are a “frequent source of distraction and embarrassment for us, particularly in recent weeks.”

The New York Times was the first outlet to report the purge, based on information from three employees familiar with the situation. The employees were not named.

It’s unclear how many SpaceX workers lost their jobs, but Shotwell left no doubt that the company believed they had crossed an unacceptable line. “The letter, solicitations and general process made employees feel uncomfortable, intimidated and bullied, and/or angry because the letter pressured them to sign onto something that did not reflect their views,” Shotwell wrote in her email, according to the Times . “”We have too much critical work to accomplish and no need for this kind of overreaching activism.”

The firings occurred Thursday — the same day Musk addressed Twitter employees for the first time about his $44 billion deal to add that social media service to his business empire. The purchase is in limbo while Musk tries to determine whether Twitter has been concealing the number of fake accounts on its platform.