This is a very controversial theme and there's different views on it. From legal, safety, and economic point of view, these people should be taken out of the country and if they want to be part of it they should file proper forms and papers for it.
Even though it may seem cruel, they are factually breaking the law in numerous ways. They enter and stay in the country undocumented. They work unregistered and do not pay taxes. Because they have lower demands for wages they take away the jobs of millions of American citizens. Also we should take in consideration that there are hundreds of millions of people from all over the world that file in proper forms and papers to get a working visa and after some time citizenship, thus it makes no sense to restrict some people and carefully choosing who can come in and who not, and on the other side allow illegal immigrants in the country.
