To be sure, there certainly are many, many ways to break an egg, but this article is specifically talking about device-resident code that would take care of bricking the phone for you...no need to mess with HLR's. One-stop shopping, as it were :)
If so, they are barking up the WRONG tree. We don't want the handset software to do the banning. Banning an ESN is *easy* compared to what they are describing here. Carriers only have to check the ESN registry when the handset gets turned on, if it's not "bad" and a it has a valid SIM so you know who to bill, it's good to go. The other advantages is that it is NOT reversible by the criminal, while re-flashing the phone is something they might be able to accomplish. Yet, upon recovery of a stolen phone, a bad ESN registry might allow for the reinstatement of of an ESN by the owner so they can use it again.
Yeah, there's definitely lots of potential problems with this whole scheme, which is why most people here are saying 'hell no'.
Even if you ignore the potential for abuse (kill-codes being sent by someone not authorized by the user), how effective can it really be? Basically, unless the reset password is hard-coded *someone* will find a way to change it, and even if it is hard-coded, chances are a patient enough thief will recover it...eventually. Firmware can be flashed, chips can be swapped out and probed, etc. etc.
The only way I can see that this could be really effective at the stated goal of reducing theft is if the phone *physically* bricks on receipt of the kill code, like if an acid capsule were punctured to etch the boards beyond repair. It's non-recoverable by anyone, which sucks for the user, but at least the thief isn't getting more than parts value for the stolen goods and the user's data is safe from malicious intent.
Even in this case, though, the thief will simply make it a priority to get the device into a faraday cage right after 'acquisition', so the user doesn't have time to get the kill code sent...then they have all the time in the world to disable the theft countermeasures. Be suspicious of that man following you with the roll of tinfoil in his back pocket...