After some initial research, I can report that the Facebook group called Teen Science Cafés Rock! is now a closed group. This means that anyone can search for it and request to join, but only members can see the activity. I have removed all adults except for the Joe Barista facebook account which I use to conduct TSCN business. As of now, the settings are such that anyone can add members, but only the admin (Joe Barista) can approve them. If one of your Teen Leaders would like to become an admin (there can be more than one), please let me know and they can take over that duty.
The direct link for the group is https://www.facebook.com/groups/teensciencecafesrock/ or your teens can search for it in Facebook’s search bar.