I disagree with the idea that an employer can demand information that the state does not require. If an employer asks for salary history, a candidate can simply tactfully say "no," and walk away if necessary. Saying no doesn't preclude working there (except in how it may agitate the negotiator). Where a candidate lives is not something you can convince the employer to negotiate without, because the state requires that information. You cannot have the job without revealing it. So I still think it's different.