Attorney General Jeff Sessions’ plan to crack down on leaks from the Justice Department and intelligence community by subpoenaing reporters would constitute a serious threat to free speech, the American Civil Liberties Union warned Friday.

Sessions announced earlier in the day that the DOJ would be reviewing its policy on issuing subpoenas to members of the press as part of an effort to prevent such disclosures.

“We respect the important role the press plays and will give them respect, but they cannot place lives at risk with impunity,” Sessions said. “We must balance their role with protecting our national security and the lives of those who serve in the intelligence community, the armed forces and all law-abiding Americans.”

The ACLU, which has frequently criticized the Trump administration for encroachments on the First Amendment, said Sessions’ crackdown constitutes a “threat” to journalists and whistleblowers.

Every American should be concerned about the Trump administration’s threat to step up its efforts against whistleblowers and journalists. https://t.co/UwdQmbtWqW — ACLU National (@ACLU) August 4, 2017

A crackdown on leaks is a crackdown on the free press and on democracy as a whole. — ACLU National (@ACLU) August 4, 2017

Our founders knew democracy depends on informed citizens and leaders can't be trusted to disclose info that reflects poorly on themselves. — ACLU National (@ACLU) August 4, 2017

These first months of the Trump administration dramatically illustrate that point. — ACLU National (@ACLU) August 4, 2017

Can anyone seriously argue our country would be better off if the public received all of its information through official channels alone? — ACLU National (@ACLU) August 4, 2017

President Donald Trump has frequently spoken out against leaks he sees as damaging to his presidency, and has threatened to come down hard on government officials speaking to the press. He also previously criticized Sessions in public for not being tough enough on leaks, and reportedly asked former FBI Director James Comey to consider jailing reporters who publish classified information.

The president’s war on leaks reportedly led him to hire Anthony Scaramucci, an outspoken former Wall Street financier, as his communications director. Scaramucci immediately set out to find and fire White House staffers who had leaked to the press, even accusing then-chief of staff Reince Priebus of leaking. (Priebus ultimately resigned one week after Scaramucci’s hire.) Scaramucci, however, was immediately fired by Priebus’ replacement, Gen. John Kelly.

Trump has also frequently attacked the media as “fake news,” and has fiercely criticized reporters for covering the FBI’s investigation into whether members of his campaign team colluded with Russian officials to influence the election, a probe he has called a “witch hunt.”