I've asked something like this while giving an interview before: "What's your greatest weakness? And don't do the thing where you turn it around to a strength."
That just really seemed to confuse people. They weren't very good candidates though.
Interesting strategy... It's something like asking "What's the number one reason I shouldn't hire you?"
I can't see a benefit to asking it, as it would only favor dishonest applicants while irritating others, but it would be interesting to hear the answers.
That just really seemed to confuse people. They weren't very good candidates though.