According to a search warrant that the FBI used to seize materials from Donald Trump’s Mar-a-Lago residence, the Justice Department is investigating the former president for potentially violating the Espionage Act.

The Espionage Act of 1917 has been used to prosecute the most notorious spies in U.S. history, including Robert Hanssen and Aldrich Ames, who are both serving life sentences for spying for Soviet and Russian intelligence services while they were working for the FBI and CIA.

The Espionage Act has long received criticism for its perceived over-aggressiveness — particularly towards journalists and whistleblowers. In an interview with Fairness & Accuracy in Reporting, journalist Chip Gibbons remarked that it was “almost impossible, if not impossible, to mount a defense” against charges under the Espionage Act.

Now, a sitting senator has called for repealing the Espionage Act altogether. In a tweet Saturday evening, Sen. Rand Paul stated, “The espionage act was abused from the beginning to jail dissenters of WWI. It is long past time to repeal this egregious affront to the 1st Amendment.”