Is it all right to stop an interviewer?

One of the things that has always got on my nerves is the ability of some interviewers to take advantage of their position of power to either minimize or disrespect a job candidate.
Some of my clients have mentioned consistently how this kind of situation usually catch them by surprise and while most have done nothing about it, there have been some who've got the tools to stop a misbehaving interviewer. The confusion comes from the lack of clarity between a 'difficult' interviewer who's got the wonderful capability to challenge a candidate beyond his/her comfort zone to prove a competency required for the job Vs. the disrespect that comes from even breaking the law (yeah, you got me right!).
So, I figure I could share with you some basics on how to handle some unusual questions and when to consider stopping an interview altogether.
#1. You are a female candidate. There's a very friendly interviewer talking about his personal stuff (beware right there!) and asking casually whether you have kids or are planning to have kids sometime soon. Your response: Is that a job requirement? Or I did not know that was a job requirement.
#2. You are a foreigner candidate with an accent. The legal question: Are you legally entitled to work in the US for any employer? Vs. the illegal one: Where are you from? For how long have you been living in the US? Every employer needs to know if you meet the basic legal requirement to work for them or not in order to consider you for a position but it is nobody's business your Country of origin or the period you've lived in the US. That could lead to ethnic related discrimination and at the end, would add nothing to the job requirements. However, a question on the languages you can fluently speak and read is a total legal one when it is job related.
#3. You are wearing a religious symbol. The question: Oh, I see you are wearing X, a close friend of mine wears the same, what church do you go to? Though it may look as a very inoffensive question, the fact is that as long as it is not a job related question it can open the door to religion based discrimination.
#4. The position requires lots of traveling as part of its job description. The legal question: Can you travel with very short notice to handle business "X where"? Vs. How are you going to handle the traveling requirements of this position with 4 kids and a cat? Have you got that taken care of? Again, who cares what you do with your personal life and caregivers? It is not a job related question if it lands into personal territory.
#5. You are a middle age candidate and an interviewer asks: “how old are you? Or how much longer do you plan to work before you retire? These questions are illegal based on age discrimination potential. However, an employer is entitled to ask you, for instance, What are your long-term career goals?

In conclusion, as a candidate make sure your potential employer compliances with the law during the interview. The rule of thumb is to ensure the interviewer asks only job related questions framed according to the law. If the interviewer persistently keeps asking illegal questions I encourage you to mention your awareness and their need to comply with Title VII of the Civil Rights Act of 1964 (“Title VII”) which is a federal law that bars employers from discriminating against any person with respect to their compensation or other terms and conditions of their employment on the basis of that person’s race, color, religion, sex or national origin.