The Mindstorms rig uses a robotic arm to tap the spacebar on the keyboard of a MacBook. That triggers its iSight camera to take a picture of an upright Kindle, with the book's text displayed on its "page." Lego "fingers" advance the next page button. The rig strikes the spacebar again, and this process runs in a loop until the book ends.
While this is happening, the MacBook is uploading these pictures of the book's contents from the Mindstorm rig to a cloud-based optical character recognition service, which pulls out any text appearing in a picture and renders it as standard plain text.
Purgathofer's device isn't to be taken as a statement on the supposed evils of e-books - he's an e-book fan. Instead, he's unhappy with the tradeoff in licensing your Kindle e-books instead of owning them.
Purgathofer says this is a project based on personal interest and has nothing to do with his professional work.
Here's a video of the DIY Kindle Scanner in action:
DIY kindle scanner from peter purgathofer on Vimeo.
Disclosure: Jeff Bezos is an investor in Business Insider through his personal investment company Bezos Expeditions.