Imagine a world in which every book, song, television programme and movie ever created is instantly available online with just the click of a mouse. Such a world would offer enormous promise not only to consumers but to artists and creators as well, who would finally be able to reach audiences that have long been too distant or expensive to reach before.

This amazing new world is almost upon us, thanks to the internet and new digital technologies for scanning and distributing vast libraries of books, video and music. But sharp debate has broken out over how best to realise the goal of such broad online access to the world’s culture without undermining the financial incentives for creativity that are so essential to the development of these works.