The fallacy of the excluded middle i.e. "I am not permitted to talk about that right here and now."
If I thought that answer were going to be consistently and uniformly applied across the board, I'd probably be less concerned that I am. But I don't believe that will actually be the case, not for a moment - as I said before, I can't help but wonder how many will choose not to hide their light under a bushel. Unless you can guarantee that the answer will be "zero", we've got a problem.