This raises issues with inter-library loans (ILL). No problems with hard copies, which are lent physically and returned. With online content, licenses do not allow to simply forward a PDF file. As Elsevier makes explicit in its policy, the requested item needs to be printed, then scanned before being send through Ariel (an electronic ILL network most libraries use). Thus, copyright rules lead to more paper being wasted because content is online. Great for efficiency and the environment.
Hat tips: Peter Suber and DigitalKoans.