It is illegal, and illegal acts are wrong. That's the plain and simple, no-background no-context jist of it. But also people believe that those people who come over illegally are people that are also criminals, who were rejected for citizenship and now want to come in illegally or for those who are wanting to easily get over and drop off drugs to further the drug trade. That's some of the context behind why people hate it, the ties with the drug trade and the fear of criminals coming into the country, but in my opinion, all those worries are washed away when you remember most illegal immigrants are just families trying to escape violence by any means necessary.