I have been away from the fray because I have out of the country for a couple of weeks.
Allow me to share my experience of traveling through Chicago O'Hare airport.
First I had a six hour lay over and plenty of time to walk around and check out everything and every one. I selected a coffee bar in the B concourse and struck a conversation with the woman working there. I asked her where she was from and she said Mexico. I asked how long she had been here, she said 2 months. I asked her if she had trouble getting a work visa, she said she didn't need a work visa. She just came here to work. I told her she couldn't just come here to work, it was illegal and walked away to a distance that I could watch. My coffee bar lady started going back and forth with the other suspicious looking cleaning people and workers at the other stands on the concourse having little conversations and glaring at me. I think I may have upset her. There were a lot of suspicious looking people working at that airport - most of them handling the food. Perhaps the rest were handling the luggage.
Then, the TSA guy that was checking boarding passes had his ID badge on one of those little ribbon clips, his was red, white and green with a little Mexican flag where it held his badge - obviously a Homeland Security Employee.

Now, upon arrival I had to walk about a half a mile from the gates through the International terminal to passport control. I had to show my passport to the customs and IMMIGRATION officers that are always at the airport I guess they don't notice the illegal's working there.
HOMELAND SECURITY IS A JOKE - they are an ineffectual money drain.
Did I mention they lost my luggage?