ERPNext is using the user email as a unique id to identify a social user.
These days most of us use multiple emails for their social identities, one for Facebook, another for Google… and an other for working with ERPNext
Social login will create a new user for each emails. If your email is different on Facebook and Google you will have two differents accounts on ERPNext. You can even have a third account if you login with the email/passwd form.
Is there a way to merge Social identities with an existing user without creating a new one? OR
allow an already connected user to add social profiles to its account?