Well, if you're going to create a "connection", which is the tie between your application user and their profile on a provider such as Facebook or Twitter, then you're going to need something on your end that represents that user.
But it is possible to not maintain a local representation of the user and instead rely on the provider-side profile as your source of user data. That's pretty much what the spring-social-quickstart sample (https://github.com/SpringSource/spri...ial-quickstart) does. It goes through the ProviderSignInController flow and creates an on-the-fly user based on the user's provider profile ID.
It's a bit simplistic, sure. But it contains the basics of what I think you're trying to do.
Spring Social Project Lead