A pity your comment is so low on the list. This isn't even borderline illegal - at least here in South Africa, if you ask a question like this of me and I don't get the job, and I think it's because I mentioned my 10 kids in answering this question, I have pretty solid grounds to charge this as a unfair discriminatory question and seek recourse from the CCMA (the legal entity that deals with these sorts of issues in SA).