Amazon may be in the process of stirring up some more trouble for itself thanks to reports that the company is deleting certain kinds of erotica from both the online store and users' devices. The erotica in question is controversial: it talks about certain acts of incest. Judging from Amazon's most recent bouts with book "censorship," users who have already paid for the deleted content are likely to get fired up.

Self-published author Selena Kitt was first notified that the print version of one of her fiction books violated Amazon's content guidelines last week, followed by the unceremonious removal of two more offerings from the Kindle store. After noticing that the three books that Amazon singled out were all "erotic incest fantasy fiction," she found at least three other authors whose incest-themed erotica had been removed from Amazon, followed by a Kindle support thread full of even more names.

"I want to be clear that while the subject of incest may not appeal to some, there is no underage contact in any of my work, and I make that either explicitly clear in all my stories or I state it up front in the book's disclaimer," Kitt wrote in a blog post. "I don't condone or support actual incest, just as someone who writes mysteries about serial killers wouldn't condone killing."

On top of the book removal from Amazon's store, Kitt's readers reportedly found that her books had disappeared from their Kindles as well. "When one reader called to get a refund for the book she no longer had access to, she was chastised by the Amazon customer service representative about the 'severity' of the book she’d chosen to purchase," Kitt wrote.

If true, then Amazon has some explaining to do. When the company "went Big Brother" and deleted unauthorized copies of 1984 from readers' Kindles, the company was slapped with a lawsuit for removing content that people not only paid for, but also made notes and highlights in. Amazon eventually settled the lawsuit late last year, and in the settlement, Amazon's attorneys agreed to legally binding terms that described its content deletion policy. When it came to books, Amazon said that deletions would only occur under a limited number of circumstances: failed credit card transactions, judicial orders, malware, or the permission of the user.

Fictional incest activities between two fictional adults doesn't appear to fall into any of those categories, but that may be neither here nor there, since Amazon's author guidelines restrict unspecified kinds of "offensive" content. This came to a head last month, when a furor rose among Internet users over Amazon's sale of The Pedophile's Guide to Love and Pleasure. Amazon eventually caved to public pressure and removed the book, despite the company's insistence that it tries to resist censorship whenever possible.

"Amazon believes it is censorship not to sell certain books simply because we or others believe their message is objectionable," the company said in a statement at the time. "Amazon does not support or promote hatred or criminal acts, however, we do support the right of every individual to make their own purchasing decisions."

Sex educator and author Violet Blue pointed out in an e-mail to Ars that Amazon's decisions here only continue to highlight the downsides to e-book DRM compared to physical books. "[Physical books] can't be taken back by the seller once you buy them, because the seller does not approve of the content," Blue said.

"I think what bothers me the most [with this situation] is the privacy issue for readers—this is actually HUGE. Especially with the egregious irresponsibility in their customer service representative department. Amazon is monitoring, watching and deciding for you what is sexually appropriate for you—their customers," she added.

Kitt has one more bone to pick with Amazon over its latest decision: Amazon's own TV ad shows a woman reading a Kindle book that details a sexual relationship between a 19-year-old and his stepmother, "which, in some states, is legally incest." Whether Amazon thinks the book in the ad is equally inappropriate will remain unclear for now, though, as Amazon did not respond to our requests for comment on this story.

Update: An Amazon spokesperson has responded to our query by saying that the books violated Amazon's content guidelines. As for the books being deleted from users' Kindles: "Due to a technical issue, for a short window of time three books were temporarily unavailable for re-download by customers who had previously purchased them. When this was brought to our attention, we fixed the problem and those books were once again made available for re-download. We apologize for the inconvenience."