President Donald Trump’s administration is being sued over Elon Musk’s alleged “massive and unprecedented” intrusion into the American government’s payment systems. The suit, filed in a Washington, DC federal court Monday evening by the advocacy group Public Citizen, calls for the court to stop the “unlawful, ongoing, systematic, and continuous disclosure of personal and financial information … to Elon Musk and other members of the so-called ‘Department of Government Efficiency (DOGE), or to any other person.”

Public Citizen filed the suit against the Treasury Department on behalf of the Alliance for Retired Americans, American Federation of Government Employees, and the Service Employees International Union days after reports emerged that Musk and DOGE had gained access to federal payment systems — and to millions of Americans’ Social Security numbers. The suit claims that the Treasury Department, led by recently appointed Secretary Scott Bessent, violated the Privacy Act of 1974 and the Internal Revenue Code’s regulations surrounding taxpayer information by letting Musk and DOGE access these systems.

“People who must share information with the federal government should not be forced to share information with Elon Musk or his ‘DOGE,’” the complaint reads . “And federal law says they do not have to.”

Lawmakers have also called for investigations into Musk’s apparent takeover of the Treasury Department. Over the weekend, Sens. Ron Wyden (D-WA) and Elizabeth Warren (D-MA) wrote to Bessent demanding to know whether he had given Musk “full access” to the federal government’s payment systems.

“To put it bluntly, these payment systems simply cannot fail, and any politically-motivated meddling in them risks severe damage to our country and the economy,” wrote Wyden, the ranking member of the Senate Committee on Finance. “I can think of no good reason why political operators who have demonstrated a blatant disregard for the law would need access to these sensitive, mission-critical systems.”

Wyden’s letter ended with a list of questions for Bessent, including whether officials associated with Musk or DOGE have requested or been granted access to the Fiscal Service’s payment systems. Wyden also asked about what information security measures were taken to ensure that Musk and DOGE’s access to government payment systems “does not result in hackers and foreign spies breaching or otherwise gaining access to the Fiscal Service’s payment systems.”

In a separate letter, Warren asked what safeguards are in place to ensure access to these systems isn’t abused, as well as what measures are being taken to protect Americans’ sensitive data, including Social Security numbers. Warren asked that Bessent respond to her questions by February 7th, while Wyden requested a response by February 12th. Neither letter specifies what happens if Bessent refuses to respond.

Bradley Moss, a national security lawyer, told The Verge that the administration could face other legal challenges to DOGE’s attempts to gut the federal bureaucracy. Organizations whose funding is cut due to the freeze in USAID payments could sue, as could federal employees who get purged by DOGE. Congress, too, could challenge DOGE’s efforts to “impound funds that Congress appropriated to particular agencies, contracts, or programs,” Moss said.

“President Trump is clearly in a ‘just do it and be legends’ phase,” Moss said. “He is pushing all the boundaries to see what he can accomplish before anyone can legally stop him, if ever. It remains to be seen if the courts will check his authoritarian actions, as it is clear Republican majorities in Congress will not.”