Immigrant workers across this country face a distinct threat: unscrupulous employers intimidate or retaliate against them if they complain about illegal working conditions. Employers actually have an incentive to recruit foreign workers because they can exploit this vulnerability to underpay and mistreat them. A shipping company called Signal International is a perfect example. In 2006, they lured more than 500 guest workers here from India under the H-2B temporary guest worker program to repair oil rigs after Hurricane Katrina. Workers were promised green cards for themselves and their...