Amazon is no longer selling a self-published guide for paedophiles after protests from customers and children's charities.
It was not immediately clear whether Amazon.com pulled the item or the author withdrew it.
The book, The Paedophile's Guide To Love And Pleasure: A Child-lover's Code Of Conduct," offers advice to paedophiles on how to make a sexual encounter with a child as safe as possible.
It includes first-person descriptions of such encounters, purportedly written from a child's point of view.
The availability of the book calls into question whether Amazon has any procedures - or even an obligation - to vet books before they are sold in its online stores.
The title is an electronic book available for Amazon's Kindle e-reader and the company's software for reading Kindle books on mobile phones and computers. Amazon allows authors to submit their own works and shares revenue with them.
Amazon issues guidelines banning certain materials, including those deemed offensive. However, the company does not elaborate on what constitutes offensive content, saying it is "probably what you would expect." Amazon also does not promise to remove or protect any category of books.
Once discovered on Wednesday, the book triggered outrage from customers on sites such as Twitter. Some people threatened to boycott the online store until Amazon removed the book. Two petitions on Facebook won more than 13,500 supporters. Child online safety advocacy group Enough Is Enough said it was not surprised someone would publish such a book, but that Amazon should remove it. It said selling the book gives the impression that child abuse is normal.
But Christopher Finan, president of the American Booksellers Foundation For Free Expression, said Amazon has the constitutional right to sell any book that is not child pornography or legally obscene. Finan said Greaves' book does not amount to either because it does not include illustrations.
The author of The Pedophile's Guide, listed as Philip R Greaves II, still has other titles sold through Amazon.