I like the idea and I was one of those who asked for it in the 'suggestions' thread. I just don't get the whole 'small fandoms'! outcry. Just HOW small are we talking about that everyone knows who you are?
Also secrets are about unpopular opinions - if they know who you are then you clearly have stated the opinion already - therefore not a secret.

I don't know, I find that making secrets and including a name on the bottom (on other comms) does not limit my liberty to say what I want to say without being found out. I really do feel safe that people will never know or at least will never be sure it's me, so I don't see how anyone could be so scared they can be found out.