Since people in this thread are trotting out the old "we have to FizzBuzz people to weed out the millions of fake coders" argument:

Remember that FizzBuzz was originally proposed as a response to the number of CS degree holders who allegedly could not code their way out of a paper bag.

I don't care if someone can derive the hierarchy of Turing degrees from first principles. I care if they can do the job I'm trying to hire for.