I bought a used iPhone 4. The previous owner re-set the phone, but did not remove the device from their iCloud. It is asking me for their iCloud information when I try to set-up the phone. I don't have contact with the previous owner anymore. Is there a way to remove the device from their iCloud so I can use a new one?
Official steps to turn off Find My iPhone Activation Lock are documented by Apple at https://support.apple.com/en-us/HT201441
In a nutshell, the various ways to remove iCloud Activation Lock include:
- Apple will remove the lock if they can verify the original purchaser is requesting the action.
- Self-service removal if you can authenticate as the iCloud account that placed the lock on that device.
- Business using DEP can often use their MDM to remove the lock as a self-service action without needing Apple to be involved.
For consumers, you will likely need to make an appointment at an Apple Store and provide the Genius on-hand proof of purchase (to show you're the authorized owner) along with proof of identity and they will reset Activation Lock, giving you access to the device.
For businesses, it depends if you are enrolled in DEP - Apple's Device Enrollment Program or just want to provide copies of the original purchase listing serial numbers to verify ownership.
If you bought the device second hand, stole it, found it or came to possess the device by some means other than buying it from Apple directly, then you will probably need the original owner to show proof of purchase, etc. They will then transfer the device to your account or simply disable Activation Lock.
The only self-service way to remove the lock if you can't type your password into the device itself is to authenticate at https://icloud.com and remove the activation lock when the device is not connected to the internet.
You cannot do anything technically to get past it. Your only method is to get back to the seller. If they have disappeared, then perhaps you might want to entertain the possibility that you have been sold a stolen iPhone.
In this instance, then rather than have a very expensive paperweight, you might want to report it to the Police. There is a slim chance that it has been reported as stolen, and they may be able to reunite it with it's true owner, in which case there is also a chance that they may reward you in some way to make up for your loss, or (perfect scenario) they will have already replaced it on insurance, and will simply unlock it for you and let you keep it.
To confirm, there is only a human solution to this problem, by getting the owner of the registered Apple ID to unlock it.
You can't just bypass it.
The very nature of Activation Lock is that it is impassible so that the device can still be tracked by the owner if it is lost/stolen. You can't bypass it — the only way to remove it is by deleting the device from Find my iPhone on iCloud.com or logging in using the Apple ID that was used to set up Find my iPhone.
You can read more about bypassing (or not) Activation Lock in the following question:
You can use this method to bypass the iCloud activation (it works only for iPhone 4) http://www.unlockboot.com/2014/03/bypass-ios-71-activation-lock-jailbreak.html