> 4. Allow multiple identities to link to a single user account Hallelujah! Finally someone like Google recommends this, so I'm no longer going to be called fo

> 4. Allow multiple identities to link to a single user account Hallelujah! Finally someone like Google recommends this, so I'm no longer going to be called for crazily overengineering it every time I suggest this... Pretty please, read points 3 and 4 from this guide and take them into consideration if you're designing any king of reusable auth-library thinggy or a framework. (If you'd also also add entity-role-based permissions so I can say "this account has role X with respect to resource Y, which grants him permissions A, B, C etc." then finally you have the minimal required imho auth/indent/perms system for your framework and I will not have to rip it off and replace it with a custom one every time, or add zillion of patches on top of it...).