I would like to understand the legal justification for AT&T to require a customer to take the data plan with an iphone.  specificaly, if a customer acquired an iphone from a former ATT customer  (i.e., bought on ebay an iphone that was no longer on contract), and simply put in their existing voice-only SIM card, what legal grounds does AT&T have to require the customer to take the data service?   in this ‘hypothetical’ case the customer has the 3G turned off and is only using the GSM voice network connection.  the iphone is being used just as any other simple voice phone would after the SIM card installed.  All local applications run (cocntacts, games, etc), but no data service other tha Wi-Fi connection.   several key legal rulings over the last 100 years have established that the phone company can not tie the service to the device unfairly and this would seem to apply here.   seems analogous to charging differently rates for Samsung versus Motorola phones with same capability.   I understand the AT&T believes and states “it is required” but i am trying to understand whether anyone has real data and info on the legal grounds for AT&T’s position here.   thanks