Traditionally, when Congress, for instance, asks for material to be declassified, the request is forwarded to the intelligence agencies where the information originated or resides. Those agencies recommend what part, if any, can be declassified without jeopardizing intelligence sources or spy craft. Then, the Office of the Director of National Intelligence coordinates the feedback from all the agencies and makes a decision.

[DNI] Dan Coats said in a statement Friday that 17 intelligence agencies he represents will provide the Justice Department all appropriate information needed for its review of intelligence activities related to Russian interference in the 2016 presidential election.

Coats also said he's confident Drug Czar Barrwill work in accordance with "long-established standards  to protect highly-sensitive classified information that, if publicly released, would put our national security at risk."

But while Trump's memorandum instructs Barr to consult with appropriate intelligence agencies "to the extent he deems it practicable" before he releases anything, it doesn't require him to do so. This has alarmed ["intelligence experts"], who have served in high-level U.S. intelligence posts

California Rep. Adam Schiff, chairman of the House intelligence committee, vowed to conduct oversight of any effort to selectively reveal and distort classified information or manipulate the declassification system.

"The clear intent of this abuse of power is to override longstanding rules governing classified information to serve the president's political interests, advance his 'deep state' narrative, and target his political rivals," Schiff said.