Interesting article in the sense that the author never once mentions anything about the legal status of the workers in question.
But I guess that's because applicants are supposed to have valid social security numbers. Maybe they even check them via computer.
I once visited one of these "hiring halls" (1970s) and accidently mixed up a couple of digits on my number. It took their computer all of 30 seconds to determine the number didn't match my name.
Yet with 30 years newer technology, it is just impossible to verify whether or not someone is legally eligible to work in the United States. < / sarcasm>