Illegal Workers in Australia

     Today I came across an article with an audio file regarding illegal immigrants in Western Australia. In the discussion a worker from the Department of Immigration, Sian Manton speaks of the sting that took place this month in an orchard just outside of the town Gingin.
     A local tipped off the Department of Immigration which led to a roadside traffic stop in which two vans on the way to the orchard were stopped and then illegal workers were detained. Of the people detained, 24 were Malaysian and 3 were from Indonesia. 11 of the people had overstayed their visas, 16 had visas that did not give them the right to work; all of the people are in detention and will be sent back home. All of the immigrants arrived by air with legal visas, whether short-term or not.
    I thought this was a pretty interesting article to compare to the illegal immigration in America. I am curious about statistics regarding how many people in America overstay their visas to work. I also wonder how many people plan to follow their visa's regulations initially, but come across economic incentives which lead them to overstay their visas.