A group of Amazon engineers said they’re being investigated by the company after they criticized the breakneck expansion of artificial intelligence data centers and called for stronger government regulation.

Earlier this month, five Amazon employees testified at Seattle City Council meetings where officials sought public feedback on a year-long pause on the construction of new large-scale data centers to give the city time to regulate the projects. Seattle passed the moratorium in a unanimous vote on June 9.

The employees criticized the hefty AI spending of tech companies, describing it as an “all-costs-justified AI build out.”

Following the hearings, three Amazon workers were separately invited to Zoom meetings with a human resources representative who said he was investigating a concern that was raised about their testimony, according to a complaint filed Friday with the Seattle Office for Civil Rights.

The employees were informed that the investigation could lead to disciplinary action, the complaint states, while one staffer was told that the potential discipline could range up to termination.