"Amazon textbook rentals: fine-print bans taking books over state lines", reposted and commented on by Cory Doctorow on Aug 19, 2013.
Seems his original source was here: InsideHigherEd.com, a news item reported on August 16, 2013 by Lauren Ingeno. Her post notes this applies only to the Amazon Warehouse Deals.
We wonder if someday this could have implications for used book sellers offering their wares via the Amazon Marketplace.
I love this part of Ingeno's report:
The “textbooks with borders” condition applies only to books rented through Warehouse Deals and not any other third-party sellers, according to Amazon.com. When asked why the condition was put into effect, multiple customer service representatives said they did not know. Amazon public relations representatives did not respond to repeated requests for comment.
In other words, it's business as usual! :)