A senior U.S. lawmaker says representatives of Elon Musk were granted “full access” to a U.S. Treasury payments system used to disperse trillions of dollars to Americans each year, and warned that Musk’s access to the system poses a “national security risk.”

After forcing out a top official at the US Treasury Department, it now appears that Elon Musk has seized control of the government's payment system — with free rein to do what he wants. Over the weekend,