Book: The Prisoner Of Azkaban In an attempt to protect Hogwarts from the notorious criminal Sirius Black, someone thought it was a good idea to use Dementors as police guards. This is fine for criminals who were serving their time in Azkaban prison, but to allow them next to children as young as ten who are trying to attend school is a bit much. Not only are Dementors appearance terrifying with their long black cloaks and creepy faces, but they also exude sadness and can end someone's life in the most petrifying way. They live off hope and suck it from people, so who thought it was a good idea to let these guys roam around the castle grounds? Well, they weren't exactly given permission to roam round the castle grounds but they're Dementors, they don't adhere to social norms. So when Harry is doing what he loves and looking for the golden snitch during a quidditch match, before you know it, he's fallen off his broom and the ground is fast approaching.
