Not long ago TiPb reported AT&T forcing every iPhone user who is not using a iPhone data plan onto the correct plan and possibly hitting you with extra charges. Now it seems AT&T is finally making good on that promise as Erica Sudan, over at TUAW, is now reporting AT&T is planning on dumping iPhone GoPhone accounts. TiPb thinks this is AT&T finally flipping the switch on iPhone users subscribed to non-iPhone data plans and GoPhone accounts are also falling victims in all of this. The following text message is being sent to various AT&T customers:

AT&T Free MSG: A new software upgrade for iPhone will be available on 6/17. This upgrade may affect your data service. Please visit att.com/iphone or call 800-901-9878 for a representative. If you download the software and are not on an approved iPhone data plan, your data service will be interrupted.

So AT&T is using the 3.0 software as it’s excuse to flip the switch, but exactly how would they know what software you currently are on? The only way would be if iTunes reported back to Apple and then they give the information to AT&T. That scenario is highly unlikely.

Anyone not on a iPhone data plan and using an iPhone get this text message yet? Be warned fellow GoPhone and non-iPhone data plan users…