Note: I'm not a lawyer so don't take this as legal advice.
My understanding is that it is illegal to use any of those things to discriminate against someone for purposes of hiring. It's not technically illegal to ask the question, but if you do, and you don't hire the person, have fun in court trying to prove that you didn't hire them for some other, valid, reason. So don't ask them, because there's no upside in it for you.
My understanding is that it is illegal to use any of those things to discriminate against someone for purposes of hiring. It's not technically illegal to ask the question, but if you do, and you don't hire the person, have fun in court trying to prove that you didn't hire them for some other, valid, reason. So don't ask them, because there's no upside in it for you.