There's a feature where you can post to groups anonymously, still using your real account, rather than creating a new account with fake data to make you appear anonymous.
There's a dead comment sibling to this one talking about how group admins can see through the anominity. I don't understand why it is dead. It wasn't even rudely stated. Is it just flat wrong, or did it cross some unknown social boundary by pointing out a fact? Was it edited posthumously?
Edit: And, when I refresh it's not dead... I don't understand this system apparently.
Just to add to this. If the anonymous post was made on a group, the group administrators could still see it. So it's only anonymous for the rest of the (non-admin) group members.