I'd like to add a few things: 1) This is really a fundamental limitation of all encryption: It hides what you are sending, but not the fact that you are sendin

I'd like to add a few things: 1) This is really a fundamental limitation of all encryption: It hides what you are sending, but not the fact that you are sending something. Paging in mobile networks is a broadcast message that basically just says "Device with ID XXXX, please wake up and check in with the network". If you can cause pages (by calling, texting or with Facebook messages) then you can see in what area the pageing is sent, and you can find out the ID (TMSI) of the device. 2) It is not a crash report, but a connection failure report. 3) During the initial connection, before encryption is started, an rogue transmitter can send a connection rejection message to the phone, pretending to be the network. The phone will not try 4G/3G again and downgrade to 2G. The attacker can then break the weak 2G authentication and make the phone believe that it is a real base station. The last part is what an IMSI catcher / Stingray device does.