Amazon.com's Kindle e-book reader is coming under assault by hackers, who say they've figured out ways to export protected content for use on other devices.

Amazon sells content for the Kindle in an ".azw" format, some of which is has DRM (digital rights management) technology, which prevents a file from being transferred to an unauthorized device.

But one hacker, who goes by the handle "I love cabbages," with a heart to designate "love," developed a program called "Unswindle" that can convert books stored in the Kindle for PC application into a different file format that can then be imported to another device. Unswindle must be used with MobiDeDRM, another hacker program that can convert protected Amazon content.

The blogger wrote that a new version of Kindle for PC doesn't appear to interfere with Unswindle.

"We'll see if Amazon throws out another new build in short order," I love cabbages wrote on Tuesday in an update to a Dec. 17 blog post.

According to comments on the blog, some people found Unswindle worked while others encountered errors.

"I've been aching for someone to un-DRM Kindle4PC," wrote a user who goes by the name Lance." "A few of my textbooks for this semester and next are only available on Kindle and dead tree. I have an e-ink reader already so don't want to buy a Kindle, but the $10 Kindle book is so much better than a $30 paper book, not to mention it's reflowable and I can more easily make it fit my eSlick's screen."

Along the same lines, an Israeli programmer claims to have also reached the same end although by different means.

Amazon officials in the U.S. and U.K. were not immediately available for comment.

pcworld.com