They have far better things to be doing than finding out who wrote anon questions. I work in a government department with access to vast amounts of personal data on people, the curiosity wears off after the first day. Big brother doesn't really care that much unless it is relevant to operations (Whole different area of moral debate there but anyway just used it as an example)
I see your point, but why are you anonymous then? ;P I think those that go anonymous care mainly about the general users of G@G and want to hide their usernames from the people that post often and are more likely to remember what they've said.