A new report is calling attention to a secret Justice Department surveillance program in which airplanes can be used to intercept cell phone communications.

The "dirtbox" technology acts like a cell phone tower and is able to scan thousands of phones searching for a suspect. In the process, however, the plane is also pulling in the data of everyone else in that target area. 

Here's more from the Wall Street Journal report:

Cellphones are programmed to connect automatically to the strongest cell tower signal. The device being used by the U.S. Marshals Service identifies itself as having the closest, strongest signal, even though it doesn’t, and forces all the phones that can detect its signal to send in their unique registration information.

Even having encryption on a phone, such as the kind included on Apple Inc. ’s iPhone 6, doesn’t prevent this process.

The technology is aimed at locating cellphones linked to individuals under investigation by the government, including fugitives and drug dealers, but it collects information on cellphones belonging to people who aren’t criminal suspects, these people said. They said the device determines which phones belong to suspects and “lets go” of the non-suspect phones.

The device can briefly interrupt calls on certain phones. Authorities have tried to minimize the potential for harm, including modifying the software to ensure the fake tower doesn’t interrupt anyone calling 911 for emergency help, one person familiar with the matter said.

The program cuts out phone companies as an intermediary in searching for suspects. Rather than asking a company for cell-tower information to help locate a suspect, which law enforcement has criticized as slow and inaccurate, the government can now get that information itself. People familiar with the program say they do get court orders to search for phones, but it isn’t clear if those orders describe the methods used because the orders are sealed.

Also unknown are the steps taken to ensure data collected on innocent people isn’t kept for future examination by investigators. A federal appeals court ruled earlier this year that over-collection of data by investigators, and stockpiling of such data, was a violation of the Constitution.

On America's Newsroom, Fox News chief intelligence correspondent Catherine Herridge reported the latest details, saying officials are not denying the existence of this program, run by the U.S. Marshals Service.

Herridge said that this technology was developed in the 1990s by the intelligence community to be used overseas to intercept foreign communications. 

The ACLU decried the program as another "inexcusable" example of "dragnet" surveillance tactics being used domestically.

She said Justice Department officials told her that in their view, the program meets the required legal standards and agents need court approval before using this tactic.

Watch her full report above, and read more from the Wall Street Journal.