Simple Cellphone Security

Cellphones which use SIM cards, such as those used by T-Mobile and at&t, are superior to non-SIM phones, such as those used by Sprint and Verizon, for a number of reasons, which I won't go into here because I'll forget the idea by the time I'm done if I do. One major drawback, however, is security. If somebody steals your phone, all they have to do is take your SIM out and put their own in and they've got a new phone. Even if you report your phone stolen, very few, if any, carriers will hotline (lock down) the IMEI (a phone's unique serial number) to prevent it from being used on another account. Let me assure you, this is a policy, not a limitation, because they do it for phones that are stolen before they get sold at a store, thus protecting their own interests, but that's another issue that I'll let someone else fight out in court. All they do is deactivate your SIM, which is very easy to remove and replace.

So my idea is to have a tiny, 3- wheel combination lock built into the phone that physically prevents the back of the phone's casing from being removed without permanently damaging the internal circuitry. The lock can be very small, and need not add much weight or bulk. Think along the lines of those tiny suitcase locks. In the event that you need to replace the SIM or battery and forget the combination, simply take it to your local carrier's store, provide photo ID to prove that the IMEI is registered to you, and they can open it with a special key, like the TSA uses to open approved luggage locks. To prevent unscrupulous store sales agents from making a copy of the key or stealing the key, it would be mounted in a machine, like a drill press, that is bolted to the countertop.