US justice officials are scooping up mobile phone data from unwitting Americans as part of a sophisticated airborne surveillance program designed to catch criminals, the Wall Street Journal reported Thursday.

Small aircraft deployed by the US Marshals Service from at least five major airports have been taking to the skies with "dirtbox" equipment designed to mimic signals from cell towers, according to the Journal.

That in turn tricks mobile phones into revealing unique identifying numbers and general locations, according to the report.

The name "dirtbox" was said to be derived from an acronym of Digital Recovery Technology Inc., the Boeing subsidiary that makes the device.

The range of aircraft in the program covers most of the US population, the Journal reported, citing unnamed sources familiar with the operation.

Details of flights were not given, but they were said to take place regularly with each outing potentially gathering data from tens of thousands of mobile phones.

The Journal reported that the US Justice Department declined to comment for the story other than to say that its agencies comply with the law when it comes to surveillance.

Mobile phones are programmed to connect with the closest signal tower, but trust signals from towers or imposters when it comes to making decisions, hackers have demonstrated.

Boxes in planes could automatically assure mobile phones they are the optimal signal tower, then accept identifying information from handsets seeking connections.

Fake cell towers could then pass connections onto real signal towers, remaining as a conduit with the ability to tune into or block digital transmissions.

Hackers refer to such tactics as "man-in-the-middle attacks."

The Journal quoted American Civil Liberties Union chief technologist Christopher Soghoian as calling the program "dragnet surveillance" that is "inexcusable."

The program is reportedly in place to reveal locations of mobile phones associated with criminals or those suspected of crimes, but collect data about other handsets that connect, according to the Journal.

After sifting through data collected, investigators could determine the location of a targeted mobile phone to within about three meters, the report indicated.

Similar devices are used by US military and intelligence officials operating in other countries to locate terrorist suspects, according to the Journal.

Trust in US authorities has already been shaken by revelations about a sweeping Internet surveillance program.