A cell phone with a GPS locator in case it's stolen. The phone cannot be powered off without entering the correct password, nor can the battery be removed without the password. To force the battery out sans password, you have to break it. In the event that that happens, a small power reserve in the phone itself releases a virus into the software, rendering the phone useless.
-- 21 Quest, Jul 11 2007

International Mobile Equipment Identity http://en.wikipedia.org/wiki/IMEI
By registering your stolen phone's IMEI on a central database, the phone is rendered useless. [reap, Jul 11 2007]

This sounds complex, and I'm sure that there is a simple solution if only there was enough motivation on the part of the manufacturers or the networks.

Can't any mobile phone be tracked at present? Or is this dependent on the SIM (which I presume the thief swaps out)? Can't you just have a PIN that has to be re- entered once per 24hr? All these solutions would be hackable, but what isn't?
-- MaxwellBuchanan, Jul 11 2007


There is a fairly simple method, the IMEI [link].

If your phone is stolen, you can register the IMEI of the handset on the central database (your carrier can do this for you). This list is then distributed to all networks in your area, causing them to refuse to accept connections from the stolen handset.

I know a few people who have registered their stolen phones on this list and a couple who have later found their (now useless) phones. They had each subsequently been blocked by each carrier that they tried. Obviously, they were glad that the listing worked, but angry that they had disabled a phone that was in their possesion the whole time.

Although the IMEI can be reprogrammed, the methods and equipment required would make it prohibitive to your average thief who is not connected to a wider network of mobile phone thieves.
-- reap, Jul 11 2007


Or what if a circuit that encased the phone with three or more coil-like layers, two layers parallel to each other and the additional layer(s) covering any spots through which a needle could penetrate it without breaking the circuit, was fitted and wired so that if broken it would trigger a self-destruct mechanism? The circuit would encase the workings or the phone, the GPS, and a rechargeable battery. Its design involves a NOT logic gate and an analog switch. I already built the simple circuit virtually. It would need a thick protective covering to protect the system from accidentally activating.
-- bluebeaversscrubbingourfloors, Aug 25 2009


The IMEI registry is the best method, but US carriers won't do it. Not the big ones, anyway.
-- 21 Quest, Aug 25 2009



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