Hi, I have a friend who recently just bought an iphone overseas with model number MB048LL/A. From what I know, that model number is a USA set and all USA sets are locked to carrier (AT&T). However when she inserted her overseas SIM, the phone detected it just fine. Does that mean the phone has already been unlocked? Could anyone tell me if this is factory or software unlocked? If it is software unlocked, is it true that it's not safe to jailbreak or do OS (2.2.1 / 3.0) update or do any other kinds of update and app installations as freely as how a factory unlocked set could be? Could anyone pls help to give a light to this? If possible, full comparisons and limitations a software and factory unlocked set could possibly have. Thanks in advance.