I disagree. As a staffing professional, I can tell you that many companies use staffing companies to cover their use of illegals, and so they are officially clean.
Del Monte foods, for example. Many tier two auto suppliers have expressed a desire for these workers and don’t care if they are legal or not. The reason? They show up. Every day, on time, they are in the spot. However, if the staffing company does due dilligence, these days they know if the worker is using a phony SSAN.
Too many sweeping generalizations for me. What is your responsibility to comply with the law?