Some links about Amazon removing GLBT books from their rankings and search system:
From Rick Klaw: Cheryl Morgan's Blog: Something very strange is happening in Amazon land. It appears that someone at the online bookseller had decided to strip the sales rankings from any book that includes gay or lesbian romance on the grounds that this is “adult content”
From Gregory Frost: Lynne Jamneck's Blog: In a bizarre move, Amazon has stripped books that they classify as "adult" from their sales ratings, including work by Alan Moore and -- here's the kicker -- ALL GLBT titles.
ETA: From DearAuthor.com: Amazon Rank: It is akin to the bookstore removing the books from the shelves and requiring you to go to the Customer Service desk and ask for the book or author specifically. Visibility is a huge factor in sales and anyone who doesn’t believe that is kidding themselves.
ETA2: From Nicola Griffith: This means amazon.com are literally taking away my livelihood because my books have lesbian characters. This means I might starve.
ETA3: More info from DearAuthor.com: Amazon Censors Its Rankings: This post includes Amazon's response to an author who complained, making it clear that it isn't a technical glitch, but a deliberate move on Amazon's part.
ETA4: From Mark R. Probst: Yes, it is true. Amazon admits they are indeed stripping the sales ranking indicators for what they deem to be “adult” material. Of course they are being hypocritical because there is a multitude of “adult” literature out there that is still being ranked – Harold Robbins, Jackie Collins, come on! They are using categories THEY set up (gay and lesbian) to now target these books as somehow offensive.
I haven't bought anything from Amazon since the 90s, for various reasons. There are plenty of online alternatives, including: Barnes and Noble, Powell's, Mysterious Galaxy, Murder by the Book, and for all your Stargate needs there's Who North America. Or you can find other independent bookstores in the US that sell online through Booksense.
From Rick Klaw: Cheryl Morgan's Blog: Something very strange is happening in Amazon land. It appears that someone at the online bookseller had decided to strip the sales rankings from any book that includes gay or lesbian romance on the grounds that this is “adult content”
From Gregory Frost: Lynne Jamneck's Blog: In a bizarre move, Amazon has stripped books that they classify as "adult" from their sales ratings, including work by Alan Moore and -- here's the kicker -- ALL GLBT titles.
ETA: From DearAuthor.com: Amazon Rank: It is akin to the bookstore removing the books from the shelves and requiring you to go to the Customer Service desk and ask for the book or author specifically. Visibility is a huge factor in sales and anyone who doesn’t believe that is kidding themselves.
ETA2: From Nicola Griffith: This means amazon.com are literally taking away my livelihood because my books have lesbian characters. This means I might starve.
ETA3: More info from DearAuthor.com: Amazon Censors Its Rankings: This post includes Amazon's response to an author who complained, making it clear that it isn't a technical glitch, but a deliberate move on Amazon's part.
ETA4: From Mark R. Probst: Yes, it is true. Amazon admits they are indeed stripping the sales ranking indicators for what they deem to be “adult” material. Of course they are being hypocritical because there is a multitude of “adult” literature out there that is still being ranked – Harold Robbins, Jackie Collins, come on! They are using categories THEY set up (gay and lesbian) to now target these books as somehow offensive.
I haven't bought anything from Amazon since the 90s, for various reasons. There are plenty of online alternatives, including: Barnes and Noble, Powell's, Mysterious Galaxy, Murder by the Book, and for all your Stargate needs there's Who North America. Or you can find other independent bookstores in the US that sell online through Booksense.

Comments
I doubt they thought about it at all, but if the subject even came up before they went ahead with it, it was probably something like, "But only a small minority are going to complain."
They've conveniently forgotten that everyone has friends and relatives.
I'll definitely be getting my books elsewhere from now on, not that I frequented Amazon often anyway.
Another excellent source for sci-fi/fantasy, horror, mystery, and YA books is Creatures and Crooks in Richmond, VA. Their staff is friendly and if they have a few clues as to what you like, they make TERRIFIC recommendations. That's hard to find in most bookstores, anymore!
http://www.thepetitionsite.com/1/in-pro
I noted in my letter to Amazon that Deep Discount (which sells books in addition to DVDs) and iTunes were about to get all the money I'll be spending on books, DVDs and music in the future unless this appalling policy is reversed. Grr.
http://www.smartbitchestrashybooks.c
That describes how they are creating the term "amazon rank" and are google bombing the phrase :)