Though the data centers undergirding the AI boom are becoming hugely unpopular with US voters, companies like Amazon are making it clear they won’t tolerate any dissent within their ranks.

According to recent reporting from the New York Times, Amazon is now investigating three company engineers who spoke at a Seattle city council meeting in favor of a one-year moratorium on new data centers. The newspaper reports that five Amazon employees testified in public comment sessions ahead of the vote on the data center ban, which was unanimously approved on June 9.

Organizing off the clock as members of the group Amazon Employees for Climate Justice (AECJ), the workers reportedly urged the councilors to approve the moratorium. They likewise criticized the tech industry’s massive AI investment bubble, which they characterized as an “all-costs-justified AI build out.”

Soon after the activists spoke at the city council meeting, three of the five workers were called into separate Zoom meetings with Amazon’s human resources representatives. There, they were informed that the company was placing them under investigation as a result of their testimony, a legal complaint filed with the Seattle Office for Civil Rights claims.

That complaint basically alleges that Amazon violated a local ordinance barring corporations from discriminating against employees on the basis of political orientation, among other things. In particular, the AECJ complaint claims that each employee was informed that the investigation could result in disciplinary action, while at least one was told they could lose their job entirely.

As a legal filing states, the three employees “also learned that Amazon was monitoring their political advocacy before the Seattle city council and was seeking to identify additional employees who had engaged in political activities.”

One of the workers under investigation by the company, software engineer Patrick Schloesser, told the NYT that he had testified in two city council hearings. As Schloesser tells it, Amazon is trying to silence its employees, using workplace discipline to punish off-hours political activism.

“I had this rising sense of anger that Amazon is attempting to infringe on my rights to speak out politically in my city,” he told the NYT. “If we allow corporations to decide which speech is or is not allowed, that absolutely hurts democracy.”

Prior to the June 9th vote, Amazon spokesperson Margaret Callahan told Fortune that “we respect our colleagues’ right to voice their opinions.”

After news of the legal complaint surfaced however, the company seemed to change its tune. Amazon is now attempting to claim that the five workers spoke as Amazon representatives without approval — though it’s clearly taking great pains to avoid accusations of “retaliation.”

“As we looked more closely at how these employees represented themselves, and how their comments were received by others, it became clear that they may have been speaking in their capacity as Amazonians and not as private citizens,” Callahan told the NYT in a statement following the complaint.

Despite having once claimed to respect Amazon workers’ right to free speech, the spokesperson added that the company “may or may not take action based on what we find.”

More on data centers: Meta So Desperate for Compute That It’s Building “Data Centers” That Are Just Tents Filled With AI Chips