I just bought a locked 3G iphone from a person. I called AT&T from my regular phone and blocked all internet and media net use. I put my 3g sim from sony ericsson phone into Iphone. Phone is working fine and updating with ITunes too, Now weather and stocks are not updating as i blocked the internet. But now My AT&T online account shows iphone as my device. I am worried that AT&T will automatically add data plan to my phone. Note: Phone is still locked Will AT&T add data plan to my account?