Not to go off on a tangent here, but I've actually worked with H1B hi-tech workers from both Asia and Eastern Europe and they were good workers.  In the internet age, you can't lock the borders and keep computer-based work in your country and reserve that work for only American-born citizens.  A robust worker visa program can bring educated, skilled, motivated people into the country-- people who pay taxes, and in some cases create jobs.  If you are interested in an improved economy, what you really want to do is encourage these guests to stay and become citizens, not stereotype them and treat them with hostility.