The Wall Street Journal has revealed details of a secret spy program.
The newspaper says the justice department is collecting data from thousands of cell phones at major airports across the country.
The U.S. Marshals Service operates airplanes with a device (IMSI Catcher) on board that tricks your phone into thinking it is a cell tower.
Phones are programmed to connect automatically to the strongest cell tower signal, which is usually this new device at the airport. When it does, it transmits your unique registration information.
The newspaper says the technology is supposed to locate cell phones linked to criminal suspects, but in the process the government is collecting data on thousands of other people as well. (more)