I don't disapprove at all. I just factor it in if the thread takes a "interesting" turn.
I'm not sure I agree with the "anonymous" part. I think you're saying "I'll keep my email address private." To me, that's not anonymity.
Some folks choose to have unlisted telephone numbers. That's fine by me. I do think posting with you're real name or a "thinly veiled" nom de' newsgroups is valuable.