They will not use it to kill phones that are just Jailbroken, they will use it to kill phones that end up spreading malicious software. iOS already comes with a App kill switch. Apple has never used it even with apps that have easter eggs that give us free services that would cost us money to use through AT&T. The latest is Handy Light. Lets me tether to my Mac over 3G. That is $20 a month from AT&T. Apple pulled the app from the store, however if you got the app we got to keep it and it's functionality. Apple may have applied for a patent, but they will not abuse it.