From WOP's to Wet-Backs to illegal aliens to undocumented immigrants, the fact remains -- they broke the law. (By the way, for the young amongst us, WOP is an acronym. It stands for WithOut Papers.)
Recently US Supreme Court Justice Sonia Sotomayor is reported to have said that referring to illegal aliens as "criminals" seems insulting to her. That may be, but the fact remains they broke US law, therefore they ARE criminals.