US police are using Google’s Sensorvault database—which records the location of hundreds of millions of mobile phones worldwide—to identify suspects.

Investigators are increasingly requesting detailed location data for every device in the vicinity of a crime, the New York Times reported on Saturday.

Officers hope the new technique will revive cases when all other leads prove stale.

Launched in 2009, Google’s “Location History” is an opt-in service. Initially, it tracked Apple and Android devices’ GPS data to target advertisements and measure their success.

Now, Location History data feeds into Sensorvault, which in turn informs police operations.

Google employees allege individual “geofence” warrants frequently receive location information for dozens—even hundreds—of mobile devices.

The practice, Jennifer Valentino-DeVries argues, has turned “tracking cellphone users’ locations into a digital dragnet for law enforcement.”

As her piece highlights, the technique has put innocent bystanders in jail for days on end.

How should we balance personal privacy—and one’s right to innocence until proven guilty—with police investigations’ need for speed and efficacy?

Is “geofencing” uncomfortably similar to ocean trawling: indiscriminately raking up everything in its path, and throwing out incorrect catches later?

Or should law enforcement use every legal tool at its disposal to find culprits?


Credit for this article's header image goes to Getty.