If you are unsure what a GSM interceptor is or does. It basically listens into your phone calls and allows the operator to read all your text messages as well as telling the user your IMSI and IMEI numbers, these unique numbers should be private to you and your network only, so in short, this type of system is the ultimate spy device and shows the operator just about everything you do on your mobile phone. The worst this is somebody who is not official can make one of these devices for approximately £2000?