This book is mine,
This boot another,
Touch not the one,
For fear of the other!
A CURSE AGAINST STEALERS OF BOOKS
For him that stealeth a book from this library, 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 sink to
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 & aye.
-Monastery of San Pedro, Barcelona
(with thanks to Su Britton)