Elon Musk’s encroachment into U.S. governance has hit another legal obstacle.

The Electronic Privacy Information Center (or EPIC) filed a lawsuit against the Department of Government Efficiency (or, sigh, DOGE) on Monday, per the privacy-focused non-profit’s website. According to the lawsuit, DOGE and its leader Elon Musk have “illegally forced” the Office of Personnel Management and Treasury Department to disclose huge swaths of digital information about U.S. citizens to “unauthorized, untrained personnel.” The lawsuit calls Musk’s actions “the largest data breach in American history.”

All of this follows a firestorm of reports over the past couple of weeks detailing what some have called a sort of coup of the U.S. government. Musk and his team, which includes people as young as 19 years old, seized access to a system with sensitive data about government employees, like home addresses, Social Security numbers, and birth dates. Further reporting, including that of Mashable’s own Rebecca Ruiz, has painted a grim picture about what a politically motivated group of people could do with that data.

This isn’t the first and likely won’t be the last lawsuit attempting to halt Musk and DOGE in their tracks. A group of labor unions similarly filed suit against Musk this week, as well.