I’ve always loved this curse upon selfish library users who take books without checking them out. The fact that it was found written over the doors of a 16th century monastery library in Barcelona, Spain, is even more funny. And it shows how seriously even MONK librarians are about the services they provide:

“For him that stealeth, or borroweth and returneth not, this book from its owner, let it change into a serpent in his hand & rend him. Let him be struck with palsy, & all his members blasted. Let him languish in pain crying aloud for mercy, & let there be no surcease to his agony till he sing in dissolution. Let bookworms gnaw his entrails in token of the Worm that dieth not, & when at last he goeth to his final punishment, let the flames of Hell consume him forever.”

Pretty serious stuff! :-)