NeonMadman - actually, sorry, but when setting up a Facebook group , the administrator(s) can decide to click a selection that ensures NO ONE can be added to the group without their approval.
Members may tell friends about the group, and in turn that person can request to be a member. They will NOT become a member until an administrator approves it.
That is for 'closed' and 'secret' groups.
If one chooses to make the group 'public', then members can freely add whoever they want.
Clearly, though, that isn't what AAWA did, although they certainly should have, given the situation of many ex- or borderline Witnesses. I was added to the group without being consulted about it. That doesn't bother me, because I'm not trying to avoid any JW friends or family knowing about my concerns with the organization, but it could and did wreak havoc for some who were in that situation. It appears that AAWA was shooting for high numbers and failed to consider the impact for those who were added to the group.
AAWA should have been more on top of things, but I still think that Facebook's setup in this regard is problematic. Nobody should be able to be added to any group, public or otherwise, without his or her approval. If I think you might like to be in a group, there should be a mechanism for me to invite you, not add you, and you should not become a member of the group until you accept the invitation. If I have a FB friend that I think you might like to be friends with too, I can send a friend suggestion. However, you and the other person don't become FB friends until both of you approve the transaction. That's essentially how I think it should work with groups, and if it did, this would be a non-issue, since nobody who didn't actually want to become part of AAWA's group would have been in it, and as a result, nobody would have been outed to their JW friends as a potential apostate.