In some cases, local police departments bypassed the phone companies entirely and purchased their own cell phone tracking technology, it added.

Earlier this month, the U.S. Court of Appeals for the Sixth Circuit entered the fray when it ruled that warrantless cell phone tracking is permissible and does not violate an individual's Fourth Amendment protections against unreasonable search and seizure.

Jaikumar Vijayan covers data security and privacy issues, financial services security and e-voting for Computerworld. Follow Jaikumar on Twitter at , send e-mail to or subscribe to .

in Computerworld's Privacy Topic Center.