Toronto police revealed to the Star two weeks ago that they recently acquired at least one “Stingray,” a type of cellphone surveillance technology controversial for the secrecy surrounding its use and its broad privacy impacts. The force won’t say how much it paid, how many devices it owns, or when the technology was purchased. Toronto police also have not disclosed any policies related to the device, also known as an IMSI catcher, including what it plans to do with the data of thousands of innocent bystanders that will be swept up when it is used. Here’s everything we can tell you about IMSI catchers, and why you might care.How does it work?Broadly speaking, an IMSI (International Mobile Subscriber Identity) catcher mimics a cellphone tower, forcing all mobile devices within range to connect to it. In the time that the device is activated — usually under 15 minutes — it quickly captures unique identifying data from each of the cellphones within its range, and then releases those phones to reconnect to cellular networks. A “Stingray” is just one brand name; there are many makes and models. Police forces across Canada have declined to disclose which models they use, their operating range, or most other technical details, arguing that doing so would compromise investigative techniques. How do police use the technology?We don’t know all the circumstances in which police have used IMSI catchers. But through a few court cases that have come to light, we do know the devices have been used to identify unknown cellphones carried by criminal suspects — usually in major drugs, guns and gang cases, where targets often change their phones to frustrate investigators.It works like this. After getting a warrant to use the device, police follow a suspect from location to location and activate the IMSI catcher at each site, capturing unique identifiers on any cellphones carried by the suspect but also from the cellphone ...
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