http://www.uscis.gov/eir/visa-guide/h-1b-specialty-occupatio...
Thus, when I hear people complain of companies who hire H1Bs only because they want to pay them less, I always want to ask, "why haven't you reported them?"
Either they don't actually know that the companies are exclusively paying H1Bs less, or they don't believe that the government will enforce the salary floor. Either way, raising the salary floor from 1x to 1.5x probably won't address their concerns.
edited for clarity