"Common sense indicates that Canadians have a reasonable expectation of privacy in the records of their cellular telephone activity," judge John Sproat said in a court file.
Rogers and Tellus communications companies challenged Peel Region police after it obtained a court order for names, addresses and credit card numbers of thousands of their customers whose phones had pinged cellphone towers in an area where a string of jewelry robberies took place in 2014.
The judge said that Canadian police sometimes obtained orders for "tower dump" records, meaning orders for all records of cellular traffic through a certain tower over a specified period of time.
Every year such orders require communications providers to turn over personal data of hundreds of thousands, if not millions, of people.
