When a group of SpaceX workers wrote and published complaints about their new CEO Elon Musk’s tweets in an open letter last summer, they weren’t expecting executives to fire them. But a day after their public letter was published, SpaceX executives showed up, first firing five of the workers, and then firing another four employees during the next four months.

Federal law says it is illegal to retaliate against a company’s workers for trying to better their working conditions. The law also includes protections for workers who collectively share issues with their workplace.

Attorneys for the terminated group also said publicly they may privately sue SpaceX for breaking federal and state laws against discrimination.

The nine employees had complained publicly in their open letter about Musk’s numerous tweets, including his sexual comments, insults and politics, saying they believed his frequent social media posts did not show the company in a good light.

In their open letter to Musk, the workers asked SpaceX to specifically share the conduct policies for workers at the company, and then to activate these policies at every level of the company. They also requested SpaceX to address and “condemn” the CEO Musk’s “harmful Twitter behavior.”

At the time, the controversial CEO, famous for his Tweets, was facing allegations made against him in May that he had exposed himself to a female flight attendant working on a SpaceX flight. SpaceX is reputed to have paid the flight attendant a $250,000 settlement for not discussing the allegations.

When the sexual harassment scandal became public, Musk not only denied the flight attendant’s allegations but also named the claims “Elongate” and then publicly asked the alleged victim via a tweet to “describe anything at all” about his naked body. He joked about the allegations on Twitter, saying to someone, "Fine, if you touch my wiener, you can have a horse."

The SpaceX former employees’ complaint was filed with the US National Labor Relations Board by the employees to get their jobs back at SpaceX. In the documents filed with the labor board was a copy of the open letter.

In part, the letter stated, "Elon's behavior in the public sphere is a frequent source of distraction and embarrassment for us. As our CEO and most prominent spokesperson, Elon is seen as the face of SpaceX — every Tweet that Elon sends is a de facto public statement by the company. It is critical to make clear to our teams and to our potential talent pool that his messaging does not reflect our work, our mission, or our values. SpaceX's current systems and culture do not live up to its stated values.”

In a new public statement, one of the fired employees, Paige Holland-Thielen, said that SpaceX was once regarded as a very safe place to always discuss any workplace issues openly, without fear of retaliation.

"Part of what was supposed to be so great about SpaceX was that any person at any level could escalate issues to leadership and be taken seriously and treated with respect," said Holland-Thielen. "We never imagined that SpaceX would fire us for trying to help the company succeed."

Musk’s takeover of Twitter has resulted in similar public dismissals against employees who disagreed with the CEO publicly about issues.

Twitter employee Eric Frohnhoefer had replied to Musk’s tweet about an issue with the platform’s speed, which was slow, simply and gently, but was blindsided by the CEO's reaction.

Responding to Musk’s tweet “I'd like to apologize for Twitter being super slow in many countries," blaming it on "poorly batched RPCs" (remote process calls),” Frohnhoefer replied simply to correct the information.

He said Musk was mistaken about the reason why the app had issues with its slow speed.

Frohnhoefer had worked as a top software engineer at Twitter for eight years. But after this public Twitter conversation with Musk, Frohnhoefer found out he was fired. Musk had sent a tweet, that a friend of Frohnhoefer shared with him, about his being let go. Soon afterward, Musk deleted the tweet.

Frohnhoefer said he found it upsetting to discover via Twitter that he was fired for his communications with Musk.

"So that's how I found out. From that tweet," he said in an interview with NPR.”I feel like I didn't cross the line. I feel like I answered it appropriately. And yeah, obviously they saw it differently."

The Twitter CEO was also accused by numerous Tesla employees of being “rage-fired’ during an angry fit.

Musk denies these allegations.

If the labor board decides that the nine terminated workers were fired illegally, they can order SpaceX to rehire them and also offer back pay.

Whether or not this ruling will be Tweeted is still to be determined.