We are implementing login through social sites like Facebook, LinkedIn, Twitter, g+, etc., but wondering about best practices. How are folks dealing with the same user that has different email addresses tied to different social sites?
Ideally, you would let users log in as any of their social identities, yet associate all of their social identities with the same internal user record. Have folks accomplished this easily? Are there good examples of how are most sites are dealing with this?
If a user has different Social Media identities - that is their choice. If they opt to present you with a single oAuth identity and not the others (as Igor described the oAuth process) - that's their choice.
If they choose to use a single oAuth identity across all social media - great. If not - its up to them to figure out which - if any - to use with you.
Assuming they want to integrate all of them is a huge presumption on your part and a potential privacy violation