Quote from : A Gentle Madness: Bibliophiles, Bibliomanes, and the Eternal Passion for Books Book

For him that stealeth, or borroweth and returneth not, this book from its owner, Let it change into a serpent in his hand and rend him. Let him be struck with palsy and all his members blasted. Let him languish in pain crying out for mercy, Let there be no surcease to his agony till he sink 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. [attributed to the Monastery of San Pedro in Barcelona, Spain]