I just unpacked my new iPhone 6S and started restoring an old iCloud backup. When I did that I was asked to enter the password for scdance@gmail.com. Any idea why? I ignored that step for now.
Do you have any music or other content that you got through "unconventional" methods? When you restore from iCloud it will try and re-authenticate to the original purchaser email address. scdance@gmail.com seems to be quite a common one that's asked for