Is it possible for a website to allow users to log in via multiple different methods, like Facebook Connect, OpenID, etc?
Not referring to simultaneous logins of the same user, but wondering if it's possible to have multiple "SSO" options.
Is there a side-effect of a user with credentials at, say, OpenID and Facebook logging in as both, with separate session information, and "gaming" or cheating "the system" somehow?
Is that the primary reason for offering only one? Are there other reasons?
UPDATE: In an effort to clarify a bit, I should say that we'd like to use Facebook Connect, but not all of our expected users have a facebook account. The same as with OpenID, etc. We do have the need to tie user actions to a particular local 'account', which would obviously be sync'd with whichever auth-provider they used to log in (or tie in later, as with SO), but would like to offer the most convenience possible.
Perhaps we should just do in-house?