I challenge you to produce the facts that these are indeed illegal immigrants! As an HR person for a supplier to the big 3, when necessary, we hire legal aliens and monitor when their visas run out. If not renewed they are terminated! I suspect you have a personal gripe against whatever company you are working for because of their practice of employing foreigners when the fact of the matter proves that it is more economical to the company to hire part-time temps and let the agency worry about the extra benefits.
Not to be redundant but it is up to you to support your claim that subject temps are illegals. If you think they are then why don't you report them to your appropriate state agency?
How do you deal with the question of false documents? How far can you check Green Cards, SS Cards, which after all may be in a perfectly valid name. What documents do you request? Got anyone in HR who can interrogate the temps? What agency do you use? Does your company have an ownership position in the temp agency?
What about vendors for maintenance, or materials handling: are you checking documents or is your temp agency checking documents?
And when you say "visas," z-cat, I am am not talking about H1B computer people, although there are certainly too many of them around doing jobs that HR could certainly fill with residents or resident citizens, no matter how much you guys moan.
And last but far from last or least on my illegal alien bitch list, what is your company doing to train young people in Maine?
I certainly do not doubt your honesty or bona fides, but you are naive if you don't know that a false ID industry has sprung up to support illegal aliens and the people who hire them.