Are you troubled by “friends” who borrow your books and never return them? Or return them soiled and dog-eared? Atlas Obscura reports on a book that describes the drastic measures medieval librarians employed — placing curses on the heads of book thieves and mutilators.

“These curses were the only things that protected the books,” says Marc Drogin, author of Anathema! Medieval Scribes and the History of Book Curses. “Luckily, it was in a time where people believed in them. If you ripped out a page, you were going to die in agony. You didn’t want to take the chance.”

Read it all here.