The way some stalkers react when the girl isn't interested - they may unleash their frustrations through self-injury, screaming, throwing or breaking things, tantrums, violent masturbation, and other anti-social behavior.
"I just saw Mitch hitting himself in the balls, he must have some stalker rage"
Guy 1: She doesn't like you, man. Get over it.
Stalker: GET AWAY FROM ME!