I have (let them live with me). An immigrant is a human, generally escaping crappy conditions in the place where they had the bad fortune to be born, while you and I, through no action of our own, were lucky enough to be born in the U.S. (assuming you're in the U.S.). They aren't thieves trying to break into my house, steal from my bank account, or steal my car at any higher rate than true red blooded 'Murcans are, and to compare an immigrant trying to move to the U.S. to a thief shows your utter lack of humanity and humility.
What have you done to make the world a better place?