When I attempted to post my first question, before I registered, I couldn't do it -- "tags" are required, and any tag I tried to use (including just "foo") failed with a pop-up about "restricted" tags.
I suggest that anonymous questions either be fixed or turned off.
Well, that's fine and good; but the error message should read "no anonymous posts." Better yet, there should not be a form to enter an anonymous request.
Anonymous posting is likely not allowed in order to build community and to reduce spam problems on Answers.