What is a cell phone IMSI?
The international mobile subscriber identity (IMSI) /ˈɪmziː/ is a number that uniquely identifies every user of a cellular network. It is stored as a 64-bit field and is sent by the mobile device to the network. An IMSI is usually presented as a 15-digit number but can be shorter.
What can IMSI catchers do?
By putting itself between you and the cell tower, an IMSI catcher can work out your rough location. IMSI catchers do not read data stored on a phone. Instead, these devices can be used to try to intercept text messages and phone calls.
How does an IMSI catcher determine the location of a phone?
Once your phone has been tricked into revealing its IMSI, the IMSI catcher can determine your phone’s general location by measuring the strength of the signal from the phone. Measuring the strength of the signal from different locations permits an ever-more precise determination of the phone’s location.
Can a person listen to your IMSI messages?
Yes. Some IMSI-catchers can ‘intercept’ your text messages, calls and internet traffic. This means others can read or listen to your personal communications. Some IMSI catchers can even re-route or edit communications and data sent to and from your phone.
How can I tell if my phone is under surveillance?
Look for strange texts. Many spy programs are controlled remotely via coded texts. When the program is not functioning properly, these texts may appear in your inbox. If you are receiving texts with random collections of letters and numbers, your phone may be infected with spy software. Check your data usage.
How are IMSI catchers an invasion of privacy?
IMSI catchers are an enormous invasion of your right to privacy – they trick all mobile phones within a certain area into giving up information about their owner – even during what the police might describe as ‘targeted’ operations.