While I understand the theft deterrent part, I have some concerns that such a "kill switch" could create a vulnerability that could bite us in the butt. I presume Madigan and her compadres are thinking of a central control through which the switch could be activated... sounds like a very bad idea to me.
Combine it with the NSA revelations and the last few years of social media fueled uprisings and this gets my conspiracy theory engine revving...