Amazon Says Error Removed Listings

In response to nearly two days of angry online commentary, particularly on Twitter, Amazon.com said on Monday that “an embarrassing and ham-fisted cataloging error” had caused thousands of books on its site to lose their sales rankings and become harder to find in searches.

Most of the company’s online critics complained that the problem appeared to have a disproportionate effect on gay and lesbian themed books, leading to cries of censorship.

The titles that lost their sales rankings during the weekend included James Baldwin’s “Giovanni’s Room,” the gay romance novel “Transgressions” and “Unfriendly Fire,” a recently published book about the government’s policies on gays in the military.

But in an e-mailed statement that came late Monday, Amazon said 57,310 books in several broad categories had been affected, including books on health and reproductive medicine.

On Sunday night, an Amazon spokeswoman told The Associated Press that there had been a “glitch in our systems,” but the company offered no further explanation for most of Monday, allowing suspicion and conspiracy theories to run rampant.

One hacker even tried to take credit for the incident, writing on his blog that he had taken advantage of bugs in Amazon’s Web site to trick people into flagging gay-themed books as inappropriate. Thousands of Twitter users included the tag “#amazonfail” in their messages on the subject, pushing it onto rankings of the most popular topics on the site and drawing in other users.

Some affected books started appearing in searches, with sales rankings restored, by early afternoon on Monday.

Sales rankings on Amazon are important to authors because they help place books on the Web site’s best-seller lists and help shoppers find them. Many of the affected titles disappeared from basic searches so that, for example, a search from Amazon’s home page for “E. M. Forster” did not turn up “Maurice,” Forster’s classic novel about a homosexual relationship. Nathaniel Frank, the author of the well-reviewed “Unfriendly Fire,” said he could not find a link to the hardcover edition of his book last weekend.