Public libraries are en vogue again now that e-readers and e-books are so popular, and publishers are wary of the trend. To the dismay of many and the surprise of few, HarperCollins Publishers has set its e-books to expire after 26 rentals -- effectively giving them around a one-year shelf life (assuming 2 weeks per rental x 26 = 52 weeks). So now cash-strapped public libraries have to pony up license fees on an annual basis because the publisher is concerned that "selling e-books to libraries in perpetuity, if left unchanged, would undermine the emerging e-book ecosystem." In other words, HarperCollins thinks lending e-books is costing the company money it could make selling them. The publisher is the first to treat library e-books differently from hard copies, and the policy change has caused some librarians to stop purchasing HarperCollins e-books. Should the new licensing scheme become a trend, we shall see if libraries are forced to stop the electronic lending party.