Last year, a guy physically tossed my bag onto the floor because, in his words "I touched his bag in HIS space in the overhead bin". Knowing that I would be sent to jail if I hit him (I am in good shape, early 30s and 6'5" - He was short, early 50s, and not fit) I calmly put my bag back in the overhead bin. I then told him calmly that "He had better be able to run when we get off the plane in SFO."

The FAs, who were utterly shocked by the guy throwing my bag out of the overhead bin gave me ^^ and actually thanked me for "acting like an adult".

When we landed, the guy seemed agitated and kept looking at me. I just stared at him intensely. He actually ran when we got off the plane. It was quite rewarding. It is sad when things get to this point. I would not exactly call my behaviour "adult", but it was better than some of the things described in this thread!

For the record - I wouldn't have done anything to the guy. I just wanted to make his flight as miserable as he had made all of ours in F.

TFD