How many of those people can afford iPhones in the first place though?
I have no doubts that if such a system is put into place that theft/ shoplifting/ 'I-thought-I-paid-for-it's' will increase exponentially and cause problems. But given Wal-Marts clientele, I think a majority will be 'iPhoned' out from the get go.
And i bet half the people at the apple store cant afford the Bmw M5 i have....whats your point?