Cedars:
From my understanding at first the FB "Group" page was open, correct? While it was an open group, you can see members faces. In small print in the upper right corner it reads the number of members, you click on that link and pictures of members show up.....
Now if the groups is closed or private, you need to find out the difference. I'm not sure if you can see members photos.
Where the damage is done is that the "group" page was open for a while, correct? It was just recently closed or private? And if you just so happend to invite an elder or JW by accident they can see or already has seen members profiles.......