Thousands of foreign workers in the U.S. — workers here legally through a visa program that allows employers to import workers from abroad — are abused, imprisoned and exploited. And the government does little to stop it, according to an investigation by BuzzFeed News. Reporters Jessica Garrison and Ken Besinger and data editor Jeremy Singer-Vine began their investigation with the story of Marisela Valdez and Isy Gonzalez, two H-2 visa workers who peeled crawfish at L.T. West Inc. in Louisiana, where they say their employer took away their passports, sexually harassed them, forced them to…