Relaying this story from memory:
Woman - 30 something - kickboxer - lawyer - lives in SF - takes the bus to work everyday.
One morning while waiting for the bus a large man sat next to her.... pause... he turned, pulled a knife on her and told her to hand over her wallet. Scared, she fumbled around and tossed it to him. Then he asked her for the ipod she had on her. Scared again she started to take her ipod off - then in that moment she snapped - no... not my ipod - anything but my ipod - She stopped "What are you doing?" She said to him, "What would your mother think if she knew you were doing this?"
Something in what she said triggered the man. Right there he fell apart, put the knife down and started weeping. He gave her the wallet back and asked her for a hug.
"no way you just tried to rob me! Go home!"