(
iPhone
Bricking) In early iPhones, an OS update made the device inoperable when it discovered that AT&T was no longer the carrier. In 2007, the iPhone debuted as an exclusive product for AT&T subscribers; however, in 2011, that exclusivity ended. See
brick.
If the iPhone and all required termination fees have been paid, the carrier can unlock the phone for the customer, who can switch to another cellular service. See
iClone.