Amazon is no longer selling a pedophilia guide, following threats by thousands of customers to boycott the online marketplace.

The self-published book titled, The Pedophile's Guide to Love and Pleasure: a Child-lover's Code of Conduct, gives advice on how to make a sexual encounter with a child safer.

It's unclear whether Amazon.com Inc. pulled the book, or whether the author withdrew it from the online selling site.

The book was discovered online Wednesday, triggering a wave of customer outrage. Two petitions on the social networking site Facebook gained more than 13,500 supporters.

Amazon issues guidelines banning certain materials, including those deemed offensive. But, the company does specify what constitutes as offensive content.

Amazon has come under attack before for selling objectionable content. In 2002, the conservative United States Justice Foundation threatened to sue Amazon for selling Understanding Loved Boys and Boylovers.

That title is still available through Amazon.