Some anecdotal evidence: Doing my graduate degree in computer science, it was hard not to notice the lack of Americans in my classes. Sure, there were plenty

Some anecdotal evidence: Doing my graduate degree in computer science, it was hard not to notice the lack of Americans in my classes. Sure, there were plenty of Americans on the business side of school, but not engineering. I receive emails and calls from employers and recruiters weekly, and a large number of the positions require you to be a US citizen. Maybe that, combined with the fact that a lot of the good developers are already working creates a shortage of good developers available to be hired?