Tracking Criminals' Cell Phones With a Stingray

There was an interesting article in today’s Wall Street Journal about the legal implications of the police using a device called a stingray to find people.

Stingrays are one of several new technologies used by law enforcement to track people’s locations, often without a search warrant. These techniques are driving a constitutional debate about whether the Fourth Amendment, which prohibits unreasonable searches and seizures, but which was written before the digital age, is keeping pace with the times.

On Nov. 8, the Supreme Court will hear arguments over whether or not police need a warrant before secretly installing a GPS device on a suspect’s car and tracking him for an extended period. In both the Senate and House, new bills would require a warrant before tracking a cellphone’s location.

The Journal article goes on to discuss whether this type of tracking is similar to placing a GPS receiver on a car to see where it goes. The Stingray works by convincing the target cellphone to associate with the Stingray as though it was the cellphone providers tower. By using triangulation (much like your cellphone can figure out where you are without using GPS), you can figure out a pretty good idea where that cellphone is stored.

I’m not an attorney (nor do I play one on TV) but I had a few thoughts on the use of the device:

• Compared to a GPS tracker: The WSJ compared the use to tracking a car with a GPS tracker. The primary difference is that you've found the car and want to see where it is going to go versus using the technology to find the car. Based upon the technology (GSM vs CDMA), location, terrain, and other factors, you can probably start with a 5 mile radius to begin your hunt for the cellphone. Much different from placing a tracking device on a known car.
• Interactive: Based upon documentation, the Stingray associates with the cellphone to track it. This is an interactive action. Taking the network scanning analogy, you're not sniffing the network looking for a cellphone. You're connecting to the webserver to see what is there.
• Criminals are plain stupid: I'm sure the police are not rolling out this technology for your run of the mill criminal. You're probably a highly desired person. If you're a wanted man, you shouldn't be carrying around a cell phone that the police can track. Serves you right for getting caught.

I'm very curious to see how the Supreme Court rules on GPS trackers as I believe they are more passive than the Stingray.

* Copies of the slipsheets and a price quote for a Stingray from the City of Miami can be found here.

As originally posted at jayschulman.com on September 22, 2011.