AT&T has been dancing around its FaceTime restrictions for several months now. Before iOS 6 even went public, it was discovered that the carrier would block FaceTime calls over a cellular connection at its own discretion. AT&T later confirmed that users would have to be on one of its new shared data plans.
Public outcry caused AT&T to then backtrack and extend the feature to anyone with a tiered, traditional data plan and a LTE device. That still didn’t cut it. Now AT&T has updated its policy again, and subscribers with grandfathered unlimited data plans are the only ones still left out in the cold.