I had a reservation on American Airlines:
Los Angeles → New York → Boston → Los Angeles
While in New York I found that I could drive to Boston with friends. I called American hoping for at least some miles in exchange for giving them an extra seat to sell. (This was during the Christmas rush.) Instead they told me that if I didn't pay them more money they would cancel my return flight to Los Angeles.
After numerous interchanges with their customer service representatives, I found that apparently the customer is always wrong. In the twisted world of American Airlines relinquishing a leg was an "itinerary change"—and they insisted that my ticket required me to pay extra for any "itinerary change."
In the future I will do my best never to fly American Airlines again.
I guess I'm not alone in feeling this way about American Airlines. Here are a few of the images I found after a quick search for American Airlines Images. (Click the image to go to the page where the image was found.)
[Click here for "American Airlines Sucks" links that Google has indexed within the past year.]