Let me tell you a story about Canada.
A little under a year ago a 65-year-old man named Frederick "John" Hatch was found burned to death near the town of Erin, Ontario, which is west of Toronto. Hatch had last been seen alive the day before, hundreds of miles away in Nepean, Ontario, outside of Ottawa. The death was deemed a murder, but the Ontario Provincial Police (OPP) have had trouble making much headway in the investigation.
Last week, the OPP's homicide investigators got a court order allowing them to identify the approximately 7,500 phones which were "in the vicinity" of Nepean on Dec. 16, 2015 between 12:30 p.m. and 3:30 p.m, as determined by the phones connecting to cell towers in the area. The court order also allows them to send two texts (one in English and one in French) asking those identified to voluntarily fill out a survey about any information they may have about Hatch's death.
In other words, police are using phone geolocation to crowdsource clues.
“Building on the accepted practice of the door-to-door witness canvass, texting is an evolution of this investigative technique that is unique, maybe unprecedented,” OPP Detective Inspector Andy Raffay told CTV.
But such requests have a mixed history in Canada, despite the fact that they're made very often. The so-called "tower dump" requests have been challenged in Canadian court, and larger requests of the same sort have been denied before.
The case seems like a cold-case version of the FBI alert that arrived on many more phones in the New York City area in September, as authorities searched for Ahmad Khan Rahami, who was suspected of involvement with a bombing in the city two days earlier.
That alert was unprecedented in its scale and purpose, but the two feel of a piece because they 1) rely on phone data to target people based on location, and 2) employ those people in law enforcement action.
On the one hand, this seems like a powerful tool for turning up leads that has become available because we all carry around devices that allow instant communication and geo-tracking. But there are downsides. In the case of the FBI alert, there was the danger that one of the millions of people in the New York City area might decide that someone they saw was Rahami, sicking police on an innocent.
In this case, it could convince people who may have nothing to share that they do in fact know something significant, while also potentially infringing on their privacy, using location information from their phone in a way they didn't expect. And that's to say nothing of the fact that cell location data is often faulty.
Both cases are reminders that not only is your cellphone's data available, but law enforcement can and will use it (and your fellow civilians), just as they'll use social media data to try and gather information and build a case.
Plus, if you want a more Law & Order-y hypothetical: What if the murderer gets the text, too?
Ethan Chiel is a reporter for Fusion, writing mostly about the internet and technology. You can (and should) email him at email@example.com