The pivotal role that cellphone records played in two prominent New York murder trials this year highlights a surge in law enforcement's use of sophisticated cellular tracking techniques to keep tabs on suspects before they are arrested and build criminal cases against them by mapping their past movements, the New York Times reports. Cellphone tracking is raising concerns about civil liberties in a debate that pits public safety against privacy rights. Federal wiretap laws, outpaced by technological advances, do not explicitly cover the use of cellphone data to pinpoint a person's location; local court rulings vary widely across the U.S.
An Alabama sheriff told a carrier he needed to track a cellphone in an emergency involving a child – she turned out to be his teenage daughter, who was late returning from a date. The frequency and ease with which law enforcement accesses cellphone data to track people is difficult to assess. Civil liberties groups obtained data from the Justice Department through a lawsuit showing that in some jurisdictions, courts often allow federal prosecutors to track the location of cellphone users in real time without search warrants.