Intellectual property is one of the highly divisive issues in contemporary philosophical and political debates. The main objective of this paper is to explore some sources of tension between the formal rules of intellectual property (particularly copyright and patents) and the emerging informal norms of file sharing and open access in online environments. We look into the file sharing phenomena not only to illustrate the deepening gap between the two sets of norms, but to cast some doubt on the current (...) regime of intellectual property as an adequate frame for the new type of interactions in online environments. Revisiting the classic Arrow–Demsetz debate about intellectual property and the epistemological issues involved in assessing institutions, we suggest that seeking out new institutional arrangements aligned with the norms-in-use seems to be a more promising strategy in the new technological setting than attempting to reinforce the current legal framework. Moreover, such a strategy is less prone to committing the so-called ‘Nirvana fallacies’. As a secondary task, we try to cast some doubt on the two most common moral justifications of intellectual property as being able to ground the full extent of the current intellectual property regime. (shrink)