The Justice Department is rolling out a plan to put a stopper in leaks springing out across the federal government.

After repeated urging from President Trump, Attorney General Jeff Sessions announced on Friday a campaign to crack down on leakers in the intelligence community, issuing a stark warning to sources who would leak to reporters.

“I have this message for our friends in the intelligence community,” Sessions said in his prepared remarks. “The Department of Justice is open for business and I have, this morning, this warning: Don’t do it. For the past several months we have made changes and are seriously ramping up our efforts.”

The Department of Justice’s policy on media subpoenas is also under review, according to Sessions, who warned that journalists “cannot place lives at risk with impunity”:

We respect the important role the press plays and will give them respect, but they cannot place lives at risk with impunity,” he 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.

This nation must end this culture of leaks,” he went on. “We will investigate and seek to bring criminals to justice. We will not allow rogue anonymous sources with security clearances to sell out our country.

Sessions’ announcement lends formal weight to President Trump’s recent demands that the government take steps to quell leaks from the intelligence community, which have led to critical stories about the White House. Trump has castigated Sessions on Twitter, questioning his judgment and fulminating against leaks in The Washington Post and other publications.

Trump’s antipathy to leakers was made clear earlier this year after former FBI Director James Comey instructed a friend to leak his account of a conversation with President Trump to a reporter at The New York Times. In that discussion, Trump told Comey to throw journalists in jail, according to the former FBI chief’s account.

The Trump administration would hardly be the first to crack down on leakers. The Justice Department under President Obama pursued former NSA contractor Edward Snowden, who leaked sensitive information about U.S. surveillance practices to The Washington Post and The Guardian. Obama’s Justice Department also pursued Chelsea Manning, the Army private who leaked classified diplomatic cables to Wikileaks. She was released earlier this year.

The Justice Department also tried to compel New York Times reporter James Risen to reveal his confidential sources but relented after a years-long legal battle.