One may ask does this assertion of banning of these mobiles in India has any significant national security importance? No doubt, having knowledge about the IMEI number has many advantages for law enforcement and telecom service providers. The IMEI number is used by the GSM network to identify valid devices and therefore can be used to stop a stolen phone from accessing the network. If a mobile phone is stolen, the owner can call his or her network provider and instruct them to "ban" the phone using its IMEI number. This renders the phone useless, whether or not the phone's SIM is changed.
However, the bigger question is whether absence of an IMEI number per se is as offensive as to attract the “national security clause” and to brand a holder of such mobile a “terrorist”? The answer is in negative as we need to have additional information besides IMEI for national security purposes. The IMEI is only used to identify the device, and has no permanent or semi-permanent relation to the subscriber. However, many network and security features are enabled by knowing the current device being used by a subscriber.
It is clear that IMEI per se is not conclusive and sufficient to locate a holder of the mobile set. We need other important information as well. The information provided by the SIM cards to the nearest cell tower is more accurate and conclusive than IMEI numbers. The Chinese mobiles without IMEI must also communicate with the service provider’s cell towers in order to communicate and they cannot be a national security threat unless the holder manipulates IMEI, SIM and other crucial technical details and methods of a mobile set. In the absence of an “Explanation” by the GOI, the present action seems to be more guided by vested interests and industrial lobbying than national security concerns. It is also violating the Human Rights, Fundamental Rights and Consumer Rights of Indian citizens without just and reasonable cause.