AT&T has cleared the air this afternoon on its policies for FaceTime over cellular, saying that a Mobile Share plan will be required to use it — but it won't incur an extra charge apart from normal data usage. The feature, which is new in iOS 6, had caused controversy several weeks ago when it was revealed that beta builds appeared to block the service on AT&T's network by default, suggesting that the carrier might be looking to buck the tenets of net neutrality by tacking on an extra charge to enable it.

Other video calling services aren't affected

That's not to say the move isn't exceptionally hostile to net neutrality, whose principles mostly aren't enforced by law (and are showing no signs of impending enforcement) on the country's cellular networks. The move is sure to upset some iPhone users who had no intention of moving to a Mobile Share plan — which, in some cases, can be more expensive than the company's existing individual plans — and can only be described as a completely arbitrary distinction that artificially limits the capabilities of the data buckets that non-Mobile Share users have. It's easy to speculate that AT&T is looking to limit additional network saturation by limiting which customers can use the feature, but then again, that's the function that the limited data buckets themselves serve.

Customers who aren't on Mobile Share plans — which launch next week — will be blocked from using FaceTime over cellular (though it'll continue to operate normally over Wi-Fi) and can call into customer service or change their plan online to gain access. We're told that apps that offer similar video calling services like Skype and Google+ won't be affected.

Here's AT&T's full statement:

AT&T will offer FaceTime over Cellular as an added benefit of our new Mobile Share data plans, which were created to meet customers' growing data needs at a great value. With Mobile Share, the more data you use, the more you save. FaceTime will continue to be available over Wi-Fi for all our customers.