This would require the carriers to set up such an infrastructure -- and why would they? It would cost them money and they'd lose the revenue of replacement pur

This would require the carriers to set up such an infrastructure -- and why would they? It would cost them money and they'd lose the revenue of replacement purchases. Also, such a system would be ripe for abuse on multiple fronts. Someone piss you off (or, more insidiously, are they a political opponent)? Impersonate them and get their phone blacklisted. This could also potentially kill the secondhand phone market, if carriers decide they're going to brick "obsolete" phones after a couple years.