I am in the process of being shipped an iPhone from Australia by a mate of mine over there. I was planning to use it on AT&T with just a normal unlimited data plan rather than the one specifically for the iPhone (for obvious reasons). My question is whether AT&T will know that I am using an iPhone on their network despite it not being bought from the US (IMEI number?) and if they do, would they go ahead and force me on to their iPhone data plan? Surely the iPhone data plan is only for iPhones bought with an AT&T contract in order to cover the cost of their big subsidisation of the phone? I apologise in advance if this is a stupid question.