Illegal Aliens in US, Ethics of Cigarettes, Overtime Policy

A) How do you feel about companies hiring illegal aliens in the US? We have many companies and cities that tend to look the other way. Is this the case of if you are not caught it is okay or you give a person a job so that is a good thing. Or is it an issue that they can pay workers a lot less because they do not want to get caught and cannot become legal citizens. Are we exploiting people in this country too? B) In things like cigarettes and even alcohol how do we measure the ethics in these companies if they cause so many social and medical issues or is it a factor of the user abuses the product and not the product? What do you think? C) What do you think would be a reasonable policy for overtime and working employees harder? If a company says more overtime, should it be mandatory or not, for instance?