They all get phoney ID cards and Social Security numbers. The Social Security office sometimes doesn't even notify the employer that the SS number is fake for years - and even then they don't say it's fake, they say there is an error with the number, please clarify. Take the letter to the employee, and he'll come back tomorrow with another SS card.
Someone called a talk show today. Naturally I can't verify that what he said is true, but he claimed that he is an undocumented worker who uses a fake SS# on his tax form, that he was audited one year, but that the IRS didn't say anything about his fake SS#. I wouldn't be surprised if that is true. The government probably doesn't care as long as they get money out of it.
"The Social Security office sometimes doesn't even notify the employer that the SS number is fake for years"
That wasn't the cae 30 or so years ago when there was a $50 penalty for making an error in name or SS# on a report but the illegal alien crowd in Washington put a halt to it.
The SS adminastration has the capacity to enforce the law if they will only do it.