Peter,
There isn't a way to do that. When a user accesses your site using JFBConnect, the fields and information that you are requesting from them is shown in the initial authentication popup. The user can choose to allow you access to that information or not. That's how the user can protect against certain information being shown.
The Facebook API doesn't allow us to see the privacy values of the user directly. We can only get the value if the user has granted your app permission to do so. In your privacy policy on your site, terms of service, or elsewhere, you can describe how you will use that information.
Thanks,
Alex