Controlled digital lending – Wikipedia

“Controlled digital lending (CDL) is a model by which libraries digitize materials in their collection and make them available for lending. It is based on interpretations of the United States copyright principles of fair use and copyright exhaustion. Proponents argue that CDL is legal under those principles because it relies on digital rights management (DRM) to ensure that any library-owned digitized work that is in copyright is loaned for a limited period of time, and that a one-to-one ratio of owned copies to borrowers is maintained. However, opponents have criticized this interpretation, arguing that a library’s purchase of a physical book does not entitle it to produce and lend an e-book….”

Source: Controlled digital lending – Wikipedia