It's a scary thing to think about, but in most cases the police don't need a warrant to track your cellphone.
Laws vary from state to state, but Massachusetts is currently the only state that requires authorities to have a warrant before accessing all cell-site location data, past or present. 12 additional states have open cases regarding the issue, but there isn't much regulation overall.
That's why the American Civil Liberties (ACLU) created an interactive map to document cellphone tracking laws throughout the country.
According to the map, states with minimal regulation include: Texas, Louisiana, Mississippi, Alabama and Georgia. In these states, authorities aren't required to have a warrant to track an individual's cellphone.
Even more, these southern states are currently permitted to use "StingRay" devices to track people and collect data from their cellphones. StingRays are suitcase-sized devices that trick cellular phones into believing they're a cell tower.
Police officials know this is a questionable tactic for receiving information about a person's whereabouts. In fact, a police officer in Florida was recently caught telling his coworkers how to hide the source of StingRay information by labeling it as a "confidential source." This would ensure that the evidence was permissible in court.