Electronic Frontier FoundationMar 5, 2025
Cell-site simulators (CSS, also known as Stingrays or IMSI catchers) are devices that masquerade as legitimate cell-phone towers, tricking phones within a certain radius into connecting to the device rather than a tower. Our new tool, Rayhunter, can help you find them. https://www.eff.org/deeplinks/2025/03/meet-rayhunter-new-open-source-tool-eff-detect-cellular-spying
Meet Rayhunter: A New Open Source Tool from EFF to Detect Cellular Spying

Rayhunter is a new open source tool we’ve created that runs off an affordable mobile hotspot that we hope empowers everyone, regardless of technical skill, to help search out cell-site simulators (CSS) around the world.

Electronic Frontier Foundation
Show threadDaniel LakelandMar 5, 2025
@eff
My sister is absolutely convinced that Goodwill uses these to prevent your cell phone from working within the store. I am pretty convinced a used car dealer I visited is using one as well. I've got my order in for several of these devices and will be using your firmware to investigate.
Show threadEric deRuiterMar 6, 2025
@dlakelan @eff There is no way anyone is using a stingray simply to to block cell signal in a retail environment. It is way too expensive for that. There are lots of ways of doing it. https://pointerclicker.com/how-to-block-cell-signal/
How to Block Cell Signals Legally in Your House

What To Know Cell signals are often blocked for safety, preventing espionage, and disrupting terrorist activities. Materials like signal jammers, Faraday cages, and specific construction materials can weaken or block cell signals. While signal jammers

PointerClicker.com
Show threadDaniel Lakeland
@ridogi
Doesn't have to be a functional stingray but I can tell you the symptom is you get a FABULOUS 5 bar signal and ZERO bandwidth.
@eff
Mar 6, 2025 at 12:50amWeb
Show threadDaniel LakelandMar 6, 2025
@ridogi
And if you walk outside the establishment only a bit you get a much lower signal but normal bandwidth.
@eff