A secretive government program that deploys scanning devices on airplanes to track the cellphones of criminal suspects is about to become more transparent.

After conducting a review of the program, the Justice Department said it will reveal more information about how it is used, The Wall Street Journal reported Sunday.

The FBI, which uses the program, has begun to receive search warrants to use the tracking devices after ignoring the warrants for years, the report said.

The devices scan cellphone data from airplanes and sweep up information from thousands of American citizens who are not suspects in an investigation, according to the Journal.

First designed to hunt terrorists, the devices are now used to track run-of-the-mill criminals.

A spokesman said in a statement that the FBI is “examining its policies to ensure they reflect the department’s continuing commitment to conducting its vital missions while according appropriate respect for privacy and civil liberties.”