We hope you weren't planning to buy any new ebooks this afternoon — the US Kindle Store shows all titles as "currently unavailable" for purchase. Amazon hasn't given any explanation as to what's happening here; you can browse the store for books as normal, and books that were previously available show up in searches, but all pricing and purchase options have been removed. However, if you've previously purchased books from Amazon, you can still download them to your device — only the purchasing of new books has been affected. It's not just books from major publishers; Kindle magazines and Kindle Singles are currently unavailable, as well. Strangely enough, the New York Times appears to be untouched — you can still sign up for a Kindle subscription, though USA Today, the Wall Street Journal, and the Washington Post are all unavailable. Internationally, though, everything seems to be working as normal. We've reached out to Amazon to find the cause of this issue and will update with anything we find out.
Update: It looks like Amazon is slowly restoring functionality, though not all books are available yet. Fifty Shades of Grey and Defending Jacob are still unavailable, while The Hunger Games and A Dangerous Talent are now available. Magazine and newspaper subscriptions also seem to be back to normal.
Update 2: The Kindle Store seems to be back to normal. There's still a few instances of "currently unavailable" books showing up in the Kindle top 100 list, but all purchasing options have been restored when clicking through. All in all, the store was down for about one hour, and we're still waiting to hear from Amazon as to what was wrong.