Unfortunately, the state that this occurred in has considerably defanged unions. There is one for the workers of this company, and its a subset of a national union, but they have no power and the company merely humors them just for good show.

And yes, if the workers had pursued legal action, I think they would have had a case, but these people were somewhere around lower middle class or poverty level and they were very afraid of losing their jobs. Knowing them, and others who are in similar situations, I completely understand and sympathize. When you're treated like crap, but given the illusion that you're respected and needed, you'll convince yourself that everything is "good enough." I myself did it for many years.