If the seller reset the telephone prior to selling, all the previous owner's information would have been wiped out. The purchaser should have reset the telephone before using it. Who know what the previous owner had installed on the telephone, especially if it were jailbroken?
It turns out my wife spent a long time yesterday adding all of her contacts to the iPhone. Can I keep or backup/restore the contacts and wipe out everything else?
Well, there is a long way to do it, depending on your desktop computer platform, though I would have wiped the phone back to factory, the first thing, before turning it on, even.
It may be easier to data enter in all your contacts and addresses using a personal information manager program on your desktop computer, such as Microsoft's Outlook or Apple's Mail, or Google's web based email program. If all that info has been entered or stored previously, just wipe the phone and import the PIM info.
You could use iCloud. Just back up your contacts from the iPhone to iCloud. You can choose what you want synced up to iCloud, from the phone. Just choose contacts as the only thing, no apps or photos or anything other. Then do a factory reset-restore to factory of the iPhone. Then log into iCloud with the iPhone and watch your contacts magically appear on the iPhone. Just make sure you are using your Apple ID, not the previous owner's
You can also choose Erase All Settings, which gets rid of accounts for email and Apple Stores. Contents such as Contacts, Apps and Messages would remain unaffected. I did not see that choice for earlier iOS versions than iOS 6.
Thanks Doolie, we're working on the iCloud method now.
This should be done via the following?
Settings > General > Reset > Erase All Content and Settings
I suppose you can do that, though, I would just plug the iPhone into iTunes on your desktop computer select the iPhone from the "Devices" tab in the left hand "Library" column and click "Restore" from the "Summary" tab window pane that first displays when you open your iOS device in iTunes.