Forging Author Signatures is Bad

Forrest R. Smith III, a guy with a stately name but perhaps not the best conscience, carefully forged the signatures of famous authors in first edition books and sold them on eBay.

Another bookseller noticed that someone was buying first-edition books and a short time later those same books were being put up for sale, but as signed copies of a book whose author was dead, he said. - Boing Boing article

I can forge my brother's signature pretty well. I don't think he's going to become a famous author, though. Maybe he should work on that.