WASHINGTON — In a victory for privacy in the digital era, the Supreme Court ruled Friday that the Constitution protects tracking data from a cellphone, requiring police to have a search warrant to obtain cell tower records that show a person’s movement for days or weeks.

The justices, in a 5-4 decision, said the Fourth Amendment protects the data from being searched without a warrant, even though these records are collected and held by a private company, not the government. Read More.