An e-mail Amazon sent to some of its authors earlier this week was just a reminder of its policy concerning public domain works and "other non-exclusive content" and not a change in policy, an Amazon spokesperson said. "The e-mail was just a reminder of a policy that’s been in place for some time," the spokesperson said.

In part, the e-mail to authors stated: "Some types of content, such as public domain content, may be free to use by anyone, or may be licensed for use by more than one party. We will not accept content that is freely available on the web unless you are the copyright owner of that content. For example, if you received your book content from a source that allows you and others to re-distribute it, and the content is freely available on the web, we will not accept it for sale on the Kindle store. We do accept public domain content, however we may choose to not sell a public domain book if its content is undifferentiated or barely differentiated from one or more other books."