If I were her parents, I would never let her near a hammer, ever.

According to the mother who discovered this note, her 8-year-old daughter gets along very well with her older brother, Ethan. That doesn't mean this very...creative little girl can't be prepared in case something should suddenly make his stuff available. Although her mom repeatedly stressed that this was not a threat, it is notable that her plans seem to include subjecting his room and many of his belongings to humiliation even though he wouldn't be able to see it. Perhaps they got into an argument over Minecraft, since apparently they would play the game together before she suddenly manifested a desire to rip his poster apart. 

Sources: redditor lala989