I've just thought. When I was enduring my 6+ hours trying to transit Miami on my way to London I cracked what I thought was a joke when I finally got to see an immigration officer. I assumed he was almost as put out by the monstrous numbers backed up as I was. So I said, with a glance back to the body of the hall, "a bit of a joke, isn't it".
"What do you mean, it's a joke? Are you criticizing my country? The United States of America is the greatest country on earth, and you should feel privileged coming here to visit".
I muttered something about not wanting to visit, but just getting out of the country again as soon as possible.
Mistake. He didn't say a word, but gestured to another official standing nearby. Next thing I was in the famous "room" where I was incarcerated for several more hours. At some point I got out my Palm Pilot to read a book I had on it. As soon as one of the guards saw this he called out to me "put it away". I wasn't sure he was addressing me, though I suspected he was, so I continued reading. He came over, thrust his face into mine, and said "I said put it away". I asked him why, and offered to demonstrate to him that it wasn't a phone. "Put it away NOW or you'll lose it". I put it away. Never once a smile, a "sir", or a "please". Just an "I'm an immigration officer of the great United States of America and you are an insignificant worm who will do exactly what I tell you" sort of look.
And they wonder why people don't like them!