If a user makes a paste before logging in, and then subsequently logs in, that paste should be assigned to that user.
NOTE: Might be a good idea to make this optional, and/or give the option to make them immediately private or something. This should be thought out deliberately.
I think just giving users ownership should be okay. We've added the ability to make anonymous private pastes, so if they fail to make it private, they've already screwed up.
If a user makes a paste before logging in, and then subsequently logs in, that paste should be assigned to that user.
NOTE: Might be a good idea to make this optional, and/or give the option to make them immediately private or something. This should be thought out deliberately.