Penguin Group, USA has pulled all of its books out of the Kindle Library Lending program today and there's no word when its titles will be returning. In addition, Penguin has delayed the release of any new e-books into the Overdrive library lending system which powers both Kindle Library Lending and other e-book library lending programs — though non-Kindle users will still have access to borrow existing titles.

The news came as a bit of a shock today, as The Digital Shift reported surprised librarians throughout the country discovering that their patrons with Kindles were suddenly unable to borrow Penguin books. The publisher cites "security concerns" as the main reason for its decision:

We have always placed a high value on the role that libraries can play in connecting our authors with our readers. However, due to new concerns about the security of our digital editions, we find it necessary to delay the availability of our new titles in the digital format while we resolve these concerns with our business partners.

Overdrive, for its part, had little choice but to pull the titles as per Penguin's request. We can't say for sure whether this is actually about DRM or if it's related to the larger issues the publishing industry has had with e-books and Amazon's growing influence. In the end, the distinction doesn't matter much to readers and librarians, who have been caught in the crossfire. The switch from analog to digital distribution for music has been long, messy, and full of corporate power struggles. It looks like history is already repeating itself when it comes to e-books.