Take a look at this:

Does this look... somehow... adult-themed to you? (Click
here if you want to look at it in all its NSFW glory).
No?
Well, sorry, you sexually depraved deviant, you obviously don't share Amazon's family values (and shame on you, just
look at it. It's clearly promoting not only the homosexual lifestyle, but also bestiality). This is clearly more offensive than, say, the
120 days of Sodom. At least according to Amazon.com - as you may have already read,
they're removing some titles from "some searches and bestseller lists and the sales rankings from books they consider "adult themed".
Personally, I have no idea who makes the chops and why.
King and King retains its ranking, so does
The Different Dragon.
My Daddy's Roommate does not, nor does Alan Hollinghurst's
The Swimmingpool Library, or
Fingersmith, but as I said, some editions of the
120 Days of Sodom do.
I wonder where this is going, especially considering some of the other books and
merchandise allowed to keep its rating.
There's a summary of what has been going on
here in case you're interested, and
here is an affected writer's timeline.This is gonna be good, I can tell.
EDIT: And the plot thickens. A SA employee's
post on the AmazonFail proposed a different theory. According to him
(1) either a vigilante organisation comparable to Innocence Jihad during during strikethrough/boldthrough/LoLJ's been reporting books with a specific kind of tags en masse, resulting in their adult flagging,
(2) in addition to that, considering that apparently, Amazon's reporting system is not automatised, someone made "mistakes" influenced by personal bias when marking books as "adult themed" - or
(3) someone did it for the lulz.
What gets me about the whole thing are the kind of books which were affected - LGBT books, no surprise there, it's common practice that any media with LGBT content are flagged as "adult", BDSM-related books, see above, but survivors, too? And feminists? Huh.
There is also
early troll claims authorship of this and oh god,
there is a twitter and
an article on the Guardian (thanks, Bron).
Oh, I'll be needing some more popcorn for this.