But how can I gather this additional information for users of the FB interface, who sign in with their FB username?

You can't, they'll need to update those fields via Profile Edit.

And what happens to the approval stage with the CB registration - it looks like the FB users are automatically approved, without any administrator involvement.

Correct, it's single sign-on and bypasses approval and confirmation processes. Wouldn't make sense otherwise and more then likely would lose more users then would gain.

leeleefallen wrote:

Will there ever be an update that will allow the act of gathering the information that is already in there facebook profile to automatically be inputted into there profile information

No, that goes too deep into privacy controls and we prefer to distance our self from Facebooks recurring privacy concerns. We wish not to cross such a boundary and simply allow easy single sign-on. What information users provide to your site for themselves is up to them, sorry.

Thanks for the clarifications, Kyle. This certainly didn't jump out at me from the documentation. Did I miss this issue in the use cases? If not, perhaps you would consider clarifying this in the use cases for future releases?

No this is not within the documentation so you did not miss anything. The documentation is primarily an installation guide.

In our particular case, the protected content on the site isn't hugely sensitive, so I can live with FB users getting immediate access. If my content was more sensitive, I would be very reluctant to use the FB integration - which would be a shame, as it is a great facility. Again, maybe finer control over these features could be considered for future releases?

Currently there are no plans to offer such finer controls. We had discussed this internally and determined the integration would be rather pointless without the single sign-on process. The users information is considered trusted coming from a reputable source, there's no reason to need to question the registration. You are welcome to edit the source and make the change however if you see fit otherwise.