Seven years ago, police in Midlothian, Virginia, sought to identify a bank robber by asking Google to search the records of more than 500 million people who used the company's "location history" feature. That search identified 19 devices that were in or near the bank around the time of the robbery, which police winnowed down to three people, including Okello Chatrie, the man who was ultimately convicted of the crime.
Depending on your perspective, that use of a "geofence" warrant was either an unobjectionable example of smart police work or an outrageous invasion of privacy. On Monday, the Supreme Court weighed the merits of those contending views in a case that illustrates the threat that two dubious doctrines pose to Fourth Amendment rights now that Americans routinely entrust huge volumes of personal information to tech companies that help them with myriad quotidian tasks.
