Cell phone privacy
Federal prosecutors and the FBI investigating a string of robberies in 2010 and 2011 obtained a vast database of phone location records for their two suspects, Aaron Graham and Eric Jordan, using a court order sent to Sprint. The records included logs of the cell phone towers that the men’s phones connected to whenever they made or received a call, offering investigators a window into their general location. Graham and Jordan were convicted and sentenced to decades in prison, but they are appealing because their lawyers argue that the authorities needed a warrant to obtain the cell phone location information. The case puts the two convicted robbers at the heart of an intense legal debate over the meaning of privacy in the digital age.
Cell phone towers operated by Sprint/Nextel as of 2011.
A wireless phone tower's cell areas are split up into pie-shaped sectors which each emit a different frequency. A phone call's signal bounces off of the nearest sector. This "ping" can indicate a person's proximity to a certain location as well as which direction they are traveling depending on which sector is activated.