Authorize/Enable Users?

Right now, probably not. We originally (long ago) did not log the user in immediately, but we got enough requests to just auto-login that we made it the standard method. The reason that so many users gave was that the admin has the ability to get the users real email address and know that Facebook believes they're a 'real' person. I can see how, on some more private sites, this may not be the desired behavior.

What would you like to see, so we can investigate a good method further:
1) When a user registers via Facebook, they aren't logged in automatically.
2) Your plugin fires and an admin needs to approve them in Joomla (or CB?)
3) The user is not able to then log back in using Facebook (or their Joomla account depending on your JFBConnect User Type setting) until approved by the moderator.

That sound about right?

Let us do some testing. It's possible this may be pretty easy by just taking out the login command that we're calling. However, this may cause some unforeseen consequences as well.

Are you using Community Builder, JomSocial, or Kunena, or just a straight-up Joomla install? Also, are you using Full Joomla Users or Facebook Only? I'm sure you've posted this in other threads, but don't remember off-hand.

We're knee-deep into v3.1 development... so if we can find something soon to work for you, we'll try to get it in that release as an option.

Still investigating, and believe this will be in the 3.1 release for later this month. We're currently looking at using the "Block User" field in the Joomla User Manager, which is how Joomla works natively when you have it set to require approval. This should work across all integration points (CB, JS, Kunena, etc)

Not yet. The 3.1 release got pushed back due to feature creep.. both a good thing and a bad thing. This is still a feature we're planning for the next version, but it has not been implemented yet. 3.1 will be out this month, and if this feature doesn't cause any problems, it will be in it. If not, it should be in the first patch release (3.1.1) shortly after 3.1 is out.