Slender Man stabbing

On May 31, 2014, in Waukesha, Wisconsin, United States, 12-year-olds Anissa Weier and Morgan Geyser stabbed their friend Payton Leutner. They tried to kill her in the woods to impress the internet character Slenderman, so that way he would not kill their families and allow them to become his servants. She survived, and was found by a cyclist.
Weier was sentenced to up to 25 years in a mental hospital, and Geyser was sentenced to up to 40.