From The Times:
“'The conventional wisdom has been that to the extent there were violations, it was confined to a few rogue employers or to especially disadvantaged workers, like undocumented immigrants,' said Nik Theodore, an author of the study and a professor of urban planning and policy at the University of Illinois, Chicago. 'What our study shows is that this is a widespread phenomenon across the low-wage labor market in the United States.'"
They also discuss how people were penalized for trying to create a union or complaining about salary.
It is amazing how employers take advantage of those most vulnerable in our society. What a sad state of affairs for this country.