Some iPhone owners chafing at links to AT&T

"Consumers are craving greater control," says Joel Kelsey, a public policy analyst with Consumers Union. So much, he says, that "they're willing to risk turning their $300-plus investment into a brick." Some iPhone owners are dropping AT&T's network and signing up with T-Mobile, voiding the device's warranty. The problem for consumers: Carrier obsession with customer control is growing. Profit is the driver. As the USA reaches wireless saturation — meaning everybody who wants a cellphone already has one — carriers have to hustle hard to add customers and grow revenue. The real pot of gold is mobile data, widely regarded as the next frontier of wireless. That's why carriers are so hot to get their hands on the latest, coolest devices — so they can sell consumers pricey data plans. To land exclusives, carriers typically pay handset makers a certain amount of money, or subsidy, per device. AT&T, for example, pays Apple more than $300. That's why AT&T's iPhone policies are so tough: It's trying to lock down customers long enough to earn back that money.