Stingrays

Stingrays are cellular phone surveillance devices, specifically ones which function as cellular site simulators (also known as cell tower simulators). The name comes from a line of tower simulators made for law enforcement and the military by the Harris Corporation, stylized as “StingRay”. The term Stingray has since become a slang term for tower simulators in general, as well as the term “IMSI catcher”. Since cell phones are just very advanced two-way radios, they are vulnerable to this type of assault.

Stingrays are frequently rolled out to enable warrantless wiretapping on both individuals and crowds, for a multitude of reasons. Sometimes they are rolled out to find missing persons. Most people who get sucked into the net of one of these, will have it happen at a protest, political gathering or other street event. There is also nothing stopping the government from setting one up on your block if you end up on the wrong list.

Crikey, you don't wanna tangle with one of these mate!

Stingrays generally have two modes, passive mode and active mode, which each work differently:

Passive mode is when these devices are only listening. Since your cell phone's connection with the cell towers is over the air, these signals can be intercepted and analyzed. With the right scanner or SDR, even you can pick up some of these signals, but you wouldn't be able to make much sense of them.

Stingrays, however, can make sense of these signals, and extrapolate personally identifying information from them like your International mobile subscriber identity or IMSI number, giving them the nickname “IMSI catchers”. With your IMSI, they can then track you anywhere you go at their leisure, and if they feel like, hit you with active mode later.

If someone is rolling out a Stingray in passive mode, the device isn't even breaking a sweat. That is because its real venom lies in active mode, which is when the Stingray starts broadcasting like it is a real cell tower, tricking every cell phone within range into connecting to it. Since your cell phone just connects to the nearest tower with the best signal, it is not hard for a Stingray (mounted to a vehicle and a portable power source) to wedge in-between and take signal priority.

Once your phone is connected to the Stingray, everything you do can now be intercepted by the Stingray: Your phone calls, your location services, your text messages, and even your data. They can then legally pry into all of it and examine the minutiae of your life. They do not need a warrant for any of this. Even once you leave the range of the Stingray, they have you ID'd in the dragnet they set up, and may very well send more personalized Stingrays after you later (or worse, mark you for lawfare).

The best way to protect yourself from a Stingray is to STOP USING CELL PHONES!!! Not only will you neuter the power of any Stingray, but you will thwart other spies & digital stalkers as well. The human race survived without cell phones for millennia. Start looking into the old analog and manual ways of doing things, read a physical book, and touch grass.

If you absolutely must have portable computer technology on you at all times (especially at street events, or if you hang out with extremely questionable people) then perhaps consider ring zero only options that don't track everywhere you go, or maybe get into old-fashioned radio.

• EFF article on IMSI catchers at the Street Level Surveillance project