The Annelies-McCal Tapes

Is it true that you have to find out the demon's name before it can be cast out, or is it just movie stuff? The Annelies-McCal tapes are recordings of an alleged exorcism done on a young girl named Annelie-McCal in Germany in the 70s. If I had children, would I let them read Harry Potter? I would pick out for them better books that wouldn't have the lines of good and evil blurred like that. A lot of ink has been spilled over the Annelies case and that poor girl was possessed. There's lots of evidence. It's one of the favorite cases for people to poo poo exorcism because