Most of the ones in Atlanta, Denver, Chicago, and New Orleans have been.
This was the first polite one I came across in my last 5 flights, but I guess it is in your best intrest to be polite to a person prior to grabbing their junk.
There is a awesome TSA employee that works at the JAX airport. I went through there on a couple occasions and both times after seeing my military ID he gave the same spiel, he said, "Thank you for all you do for our country. I want you to know that my family and I appreciate it."