This question is for a buddy of mine. His son bought a 1st gen iPhone from a friend. They have an AT&T family plan with no data. His sons friend says he can use it as is and he won't be bothered by AT&T as that's what he's been doing for a long time. He's had it for about a week and everything seems ok. When he tries to use data he gets a message saying that he is unable to because he doesn't have a data plan which is fine for him. His dad is concerned that they will all of a sudden start getting charged for a data plan. If he goes to AT&T's mywireless site it already shows the iPhone as his son's phone. Should he be worried. I'm pretty sure the phone is jailbroke but I don't know if it's unlocked (running 3.1.2). How do I know if it's unlocked? Is it the Unlocking or the jailbreaking or the fact that it's a 1st gen iPhone that is allowing him to use it without data? Also, could I give him my 3G (running iOS4) and will he get the same message? What if he just sticks in his SIM and starts using it? What if he turns off the data portion in prefs?