hi i want to let my friend use my 3gs that is unlocked and jailbroken. they are on ATT plan with no data and would not like to use data (only use the phone itself and use WIFI). If i disable the 3g and data in settings and also disable them in sbsettings will they be fine? I heard cases of ATT just adding the data plan without consent and people not finding out til the bill comes, i guess with the imei or something. Just asking to be in the clear before I give the phone away. thanks in advance!
also their data is already blocked on their existing plan
AT&T requires a data plan with all iPhones. You may be lucky and not get the data plan automatically added, but don't hold your breath. There are no absolute guaranteed methods to prevent this from happening.