I have a #Pixel 10 Pro XL phone, which may be the first phone to give warnings when the phone connects to a rogue cellphone tower or IMSI catcher. The OS cannot block it; it can only tell you that someone read information, and it presents an alert. It says,
“Your data may be at risk. Device ID accessed. At 6:57 PM a nearby network recorded your device’s unique ID (IMSI or IMEI) while using your T-Mobile SIM. This means that your location, activity, or identity has been logged.”
I didn’t ever get an alert before walking through the building, but this time, during a 30-minute walk through the building, I got about 8 alerts, ranging between 1 and 3 minutes apart.
Using this information from repeated connections, someone can follow my movements and location; they can identify it’s me because the IMSI number is unique to my phone, so it can be an indication that someone was collecting all the cellphone information in the area, most likely law enforcement.
It can also mean that I was connecting to a rogue cell phone tower, not just an IMSI catcher, and it was an attempted Stingray attack, likely also law enforcement. If successful, they can try to see and hear what I’m doing on my phone, as my phone won’t know that it’s a fake cellphone tower.
Be aware that a rogue tower will try to negotiate your phone’s connection down to a 2G connection, which is unencrypted, providing them with access to everything that you are doing and saying. Please go into your phone’s settings and disable 2G!!
It’s been believed for some time that this technology has been used by law enforcement secretly and consistently. This is creepy and unnerving.
Turning off the phone, by the way, doesn’t stop an IMSI catcher. Your phone still responds. You need to keep the phone in a Faraday bag if you’re really concerned.
It’s a good thing that phones are now starting to inform people that they are being watched and that people will begin to see how much of an issue this is. You can assume that your local law enforcement knows where you are all the time.
I’d recommend searching for other sources to corroborate that story. A website selling Faraday bags telling you that you really need a Faraday bag is hardly a reliable source.
It doesn’t mean they are wrong. Anyway, here:
“Based on documents leaked by Edward Snowden, the National Security Agency (NSA) had already developed a technique in 2004 to locate cell phones even when they were turned off, called “The Find”, mostly used to locate terrorist suspects [36]. This was accomplished through the use of IMSI catchers, which could wirelessly send a command to the phone’s baseband chip to fake any shutdown and stay on [37]. The phone could then be instructed to keep just the microphone on, in order to eavesdrop on conversations, or periodically send location pings. The only hint that the phone was still on was if it continued to feel warm even though it had been shut off, suggesting that the baseband processor was still running. IMSI catchers used by London’s Metropolitan Police are also reportedly able to shut down targeted phones remotely [38].”
https://www.cis.upenn.edu/wp-content/uploads/2019/08/EAS499Honors-IMSICatchersandMobileSecurity-V18F.pdf