Supreme Court bans long term cellphone tracking by police without a warrant

USA Today - The Supreme Court ruled that the government cannot monitor people's movements for weeks or months by tracking the location of their mobile phones without a warrant.

... It was another in a series of digital privacy verdicts issued by the high court, following rulings in recent years that police cannot use GPS equipment to track vehicles or search cellphones without a warrant.

....In 2016, police made some 125,000 requests for cellphone location data from Verizon and AT&T alone, often involving several suspects over periods of months.