Please stop spreading this. It is just not true. Yes, plenty of employers hire foreigners for less money than they would pay a domestic worker, but in almost all cases those are illegal, undocumented workers. A work visa requires a review and certification by the department of labor to establish what the appropriate wages are in the place of employment. The process requires an ad being posted in major newspapers in the area and documentation showing that no citizen or permanent resident qualified. The work visa expires in 1 to 3 years and can be renewed exactly once, for 1 to 3 years. The renewal process requires an audit. Also, as a work-visa employee, your view of "the conditions back home" are mistaken. There are many reasons why somebody would work abroad, and escaping the backwaters for the promised land of America is more cliche than anything else. That being said, I am sure there are those who abuse the system. Like any system. But don't generalize. It's a lie, and a harmful one.
To each his/her own, it takes all kinds, and all that...
Hackers of the world, unite!