I'm very keen on document forgery (even born and raised citizens do it), these guys are not illegal.
Also, I was making sure (for tax purposes, and liabilities) that they were legit, but I do my best to make sure everyone is legal, the guys who work for me, I can safely say are legal.
If they weren't, they would have to be mighty stupid, since I do send them into government offices to pick up papers and other things for me (I hate lines and I hate going through the security measures).
Large cities such as Los Angeles have bustling document forging enterprises. I think it was Leslie Stahl on 60 Minutes who did a story on this a few years ago; within minutes she had a fake SS card, fake green card and fake CA drivers license, which were sufficient to use as proof of residency in order to get a job.