Given the library incedent earlier today, these two passages are especially relevant:
“Be ye angry, and sin not: let not the sun go down upon your wrath: Neither give place to the devil.  Let him that stole steal no more: but rather let him labour, working with his hands the thing which is good, that he may have to give to him that needeth.” (Ephesians 4:26-8)

and, ehem,
“And if any man shall take away from the words of the book of this prophecy, God shall take away his part out of the book of life, and out of the holy city, and from the things which are written in this book.”  (Revelation 22:19)