FTC Chair Lina Khan, who is testifying before Congress Thursday, has raised concerns about AI, saying enforcers “need to be vigilant early” with transformative tools like artificial intelligence.

Microsoft declined to comment. The Washington Post earlier reported on the FTC’s probe.

The FTC’s investigation into the wildly popular ChatGPT comes as artificial intelligence leaders have called for developers to hit the pause button on releasing AI tools to the public, warning the powerful technology could harm humanity. In a May hearing, OpenAI CEO Sam Altman said Congress should create robust safety standards for advanced AI systems. “If this technology goes wrong, it can go quite wrong,” Altman said.

Twitter owner Elon Musk has also been one of the loudest voices warning about the potential consequences of mainstreaming AI.

A prominent tech ethics group filed a complaint in March urging the FTC to halt further commercial deployment of the technology that powers ChatGPT. The complaint from the Center for Artificial Intelligence and Digital Policy, which is led by longtime privacy advocate Marc Rotenberg, called on the FTC to open the investigation and “ensure the establishment of necessary guardrails to protect consumers, businesses, and the commercial marketplace.”