http://www.sfgate.com/cgi-bin/blogs/hleon/detail??blogid=191&entry_id=60578
As long as there is a demand to become a working American, there will be those who sell black-market green cards. Issued by the INS, green cards are essential documents needed to verify immigrants as resident aliens with the legal right to work in the United States. With an estimated 11 million illegal immigrants nationwide, a green card is gold for those questing the American Dream--and often unobtainable.