In the last few days, word has spread among independent erotica authors on social media that Amazon was quietly changing its policies for erotic novels. Five authors I spoke to, and several more on social media, have reported that their books were stripped of their best seller rankings—essentially hiding them from casual browsing on the site, and separating them from more mainstream, safe-for-work titles.

There seems to be little rhyme or reason to what gets deranked and what doesn’t. Ann Mayburn, an erotica author, told me in Facebook direct messages that her science fiction romance featuring “vibrating alien penises and ejaculation that's purple and tastes like candied violets” still has its ranking, but another novel, a BDSM romance, has been labeled as erotica and “sent to the no-rank dungeon.”

Most people browsing Amazon books might not notice or care about the best seller rank—a number that’s based on how well the title is selling on Amazon.com—but it’s part of an algorithm that influences how the book appears in search, and whether it shows up in advertisements, including suggestions from one product to the next (“If you like this book, you might like this book”). For independent authors and booksellers, this ranking is hugely important for visibility.

Another author, who asked to remain anonymous, told me in an email that Amazon changed their ranking for titles in a series and informed them that the "erotica" tag had been applied to those books. After several emails to Amazon, they received this response:

We’ve re-reviewed your book and confirmed that it contains erotic or sexually explicit content. We have found that when books are placed in the correct category it increases visibility to customers who are seeking that content. In addition, we are working on improvements to our store to further improve our search experience for customers. To remove your book from its current categorization you will need to remove the erotic or sexually explicit content and resubmit as a new ASIN.

Author Jenny Trout had every book in her contemporary erotic romance series The Boss (written under the pen name Abigail Barnette) stripped of its rank and reclassified to remove it from the Romance category. She told me in an email that Amazon is “the bread and butter of every indie out there.” She says she sold half a million copies through Amazon in a three-year period, compared to 35,000 at every other retailer combined. Her series was de-ranked without warning or explanation.

“There's no way for an indie author to make a living without Amazon, so whatever nonsense they decide they're pulling this month is just one other thing we've got to put up with,” Trout said. “And that sucks, but they're a private business and they get to do what they want, so we can only really complain from a consumer standpoint. It's not censorship, it's just a big bullshit hassle, so there's really no recourse for us.”

Allison Kelley, executive director of nonprofit trade organization Romance Writers of America, a networking and advocacy group, told me in an email that the organization is “aware of and very concerned” about this situation, “particularly because Amazon is erroneously reclassifying hotter romance and erotic romance as erotica without explanation... While we're still researching, based on what we've seen, readers who are looking for books in certain categories aren't going to find them."

One of the most frustrating aspects of this situation for authors is that they have no idea what’s going on, and little communication from Amazon. Mayburn said that Amazon sent no warning or notice that her books had ranking removed. “All we do know for sure is that one day our books had ranks and visibility, the next there was simply a blank space,” Mayburn said. “This may not sound like a big deal, but Amazon will promote your book on their site based on, among other things, the books rank. No rank=less visibility=less new readers.”

Being in limbo is the worst part, Mayburn said. “We're business people, we adjust to the market. I've been through craziness with Amazon before, it's almost expected. It's being ignored, while having major changes made to your livelihood, that is irritating. I mean, Amazon still takes its share of my books, I'm paying them to use them, and they can't even answer an email? Nope.”