Originally Posted by JDiver
As the bag starts to move - that's when I say "Please leave my bag where I put it!"

I wouldn't hesitate for a second to say just that. Don't mess with my bag 'cause I am always courteous and legal with what I bring on board.
One time, on a rare Southwest flight, a FA asked if I would put my roller bag breifcase under the seat (I always check the suitcase) and I said no way. He said I was uncooperative. I politely replied that I was ultra coperative because I checked my main bag and as such agreed to wait in baggage claim so as not to overload the overhead bins. He moved on and harrassed someone else without comment.