An American labor agency accused SpaceX of illegally firing employees after they wrote an open letter criticizing CEO Elon Musk, creating the impression that workers' activities were under the rocket company's surveillance.

A regional director of the National Labor Relations Board (NLRB) based in Los Angeles filed a complaint on Wednesday containing eight unfair labor practice charges against SpaceX, stemming from the company's alleged actions following the circulation of the employee letter in June.

The letter, among other workplace concerns, called on executives to condemn Musk's public behavior on X - the platform formerly known as Twitter - and to hold everyone accountable for unacceptable conduct. Musk's actions included downplaying sexual harassment allegations against him, which the billionaire denied.

According to the open letter at the time, "As our CEO and most prominent spokesperson, Elon is seen as the face of SpaceX – and every tweet Elon sends is de facto a public statement by the company," the letter