source: https://www.wired.com/2017/06/researchers-use-rideshares-sni...
> At Trudeau airport, Radio-Canada detected the catcher's presence through the use of a CryptoPhone — a cellphone look-alike that emits red alerts when a fake antenna tries to catch its signal. Several red alerts were received, throughout the afternoon and early evening, in the section of the airport for U.S. departures.
source: https://www.cbc.ca/news/canada/montreal/trudeau-airport-spyi...
> The devices are operated out of at least five U.S. airports, "covering most of the U.S. population". It is unclear whether the U.S. Marshals Service requests court orders to use the devices.
Once you have a number pop up on the Stingray you distribute that person's photo to all the border agents.
Since airports are one of the very few places where you can positively identify a certain person was there at a certain time, you can combine a passenger list with a device list to get some soft matches to previously unlinked devices.
Combine that linked metadata with other dragnet metadata, and you're going to learn a lot.
There are issues with some units that downgrade your data signal to a slower connection than you would get with a normal cell tower.. but otherwise you would never know the difference.
The person you are replying to is actually making an excellent point as most current methods of detecting stingrays are heavily reliant on the "tower" moving or changing.