User location histories can help to establish where the person was in court cases. In one criminal case involving a robbery suspect named Quartavius Davis, he alleged that the tracking records obtained from his cell phone company constituted unreasonable search and seizure, which amounted to a violation of his Fourth Amendment rights.
Davis was accused of robbing several restaurants and gas stations, and the prosecution used his cell phone tracking locations to place him in “close proximity” to the particular Wendy's, Amerika Gas station and Little Caesar's restaurants when the robberies took place.
While the 11th US Circuit Court of Appeals ruled that officers have to obtain a warrant in order to track mobile users' location data, this didn't exactly help the Davis case. The court stood by the conviction by permitting his cell phone tracking records to be entered into evidence.
Chief Justice John Roberts, in speaking on the digital era practice of searching cell phones during arrests, stated that it is not something that police can do routinely upon arresting someone. He stated that a warrant must be obtained. Exceptions that the court passed along included that if a child kidnapping suspect or bomb suspect is arrested.
It's an issue of privacy, as the federal court ruled. This was not the first time that courts have wrestled with the matter of warrants and cell phone tracking. In 2010, in Philadelphia, an appeals court ruled that a search warrant is not needed for police to track cell phone locations, but that judges may on a case-by-case basis elect to sparingly require a warrant.
Civil liberties groups are voicing their concerns over privacy matters related to this situation.