Currently I am the only white guy in a startup composed of Chinese and Indians. Some dev staff is overseas. I hear the green cards discussing their status all too often.
Not one person is doing something that could not be done by Americans, and indeed, I know of many, many Americans with the required specialized skills who cannot get work.
Earlier this year I interviewed at a a large company with a department having the majority of staff in India, and of the US staff in this department, half were employees and the other half contractors. All of the work could have been done by US citizens, and by employees and not by temp labor. That company makes plenty of profit, but doesn't share it.
Sometimes I wonder who exactly set this whole H1B thing going, who are the bastards who started the race to the bottom and destruction of American labor? Finance guys and think tanks lobbying the scum in Washington? Because this is not just some CEO getting smart. It's a movement, it's been pushed.