A leading teachers’ union and allied labor groups sued three Trump administration agencies on Monday to halt billionaire Elon Musk’s government-efficiency operation from accessing sensitive federal data.

The American Federation of Teachers, the National Active and Retired Federal Employees Association, the International Association of Machinists and Aerospace Workers, and the National Federation of Federal Employees filed suit in a Maryland federal court, alleging that the Treasury Department has disclosed the contents of a government system that includes records on Americans’ tax refunds and Social Security benefits.

The labor groups further accused the Education Department of improperly disclosing information in its national student loan data system that carries sensitive financial records for nearly 43 million borrowers. And they accuse the federal Office of Personnel Management of allowing Musk’s representatives access to information on millions of current and former federal employees, plus federal job applicants.

The legal complaint backed by the nonprofit advocacy group Protect Democracy and the Munger, Tolles & Olson law firm amounts to yet another challenge to the sweeping access and authority granted since Trump’s inauguration to the so-called Department of Government Efficiency.

“Steamrolling into sensitive government record systems threatens to upend how these critical systems are maintained and compromises the safety and security of personal identifying information for Americans all across the country,” the lawsuit alleged.

“It also violates federal law,” said the lawsuit, which alleges the government disclosures to Musk’s operation break the federal Privacy Act of 1974.

Representatives for the Education Department, Treasury Department, and Office of Personnel Management did not immediately respond to requests for comment.

The complaint asks a federal judge to prohibit the government agencies from allowing DOGE representatives further access to sensitive information — and requires the Trump administration “to retrieve or ensure the destruction of any copies of any records that were unlawfully disclosed” among other requests.

“Elon Musk and his minions are stealing Americans’ private personal and financial data in one of the biggest data hacks in U.S. history,” AFT President Randi Weingarten said in a statement on Monday. “I suspect no one who voted for Donald Trump thought he would allow Musk permission to invade their privacy. This is a breach of our fundamental freedoms.”

Musk’s DOGE in the past few weeks had begun a wholesale effort to cut parts of the federal government, including USAID, the Consumer Financial Protection Bureau, and Education Department.

“Government agencies are not private entities that billionaires can simply buy and rummage through,” IAM Union International President Brian Bryant said in a statement. “Congressional oversight, advocacy and voting are how we make government work for us, not reckless takeovers that put the personal data of millions of Americans into the hands of unqualified, unvetted political operatives.”