After the stabbing incident involving pre-teen girls in Wisconsin, Slenderman creator Eric Knudsen expressed his sympathy to the 12-year-old girl who was wounded by her two friends who happened to be fans of the fictional Internet game character.

Police and people who have heard about it were surprised by the reason provided by the two girls in harming their friend. The pre-teen Wisconsin girls said that they wanted to impress Slenderman by killing. However, the fictional character creator stressed in an e-mail released and published at abcNews and various online sites that he and Creepypasta administrators are "not teaching children to believe in fictional monster nor [are we] teaching them to be violent".

Several parents were alarmed by the tragedy and felt worried if their children understand the video games and horror stories found in the Internet. The increase in Internet user population keeps coming up and it seems open to all ages. In spite of warning in several Web sites that the contents are for ages 13+ or 18+ people, administrators can't easily detect the real age of the surfers. This is when parents or guardians have to come in, reminding young kids and teens to not enter any online sites that are not meant for them.

For others who don't pay attention to faceless Slenderman who wears dark suit, they start to search about the character to know who this fictional character is. Slenderman sometimes revealed himself with octopus-like tentacles still in his dark-suit trademark and haunts children, especially those who are trying to uncover him.

Many participants in the Creepypasta where Slenderman's monstrous character originated since 2009 reiterated that there is no way that the character urges anyone to harm or kill anyone and that all stated in the story they themselves created are purely fictional, which is clear that he doesn't really exist in the real world.