Ownership of intellectual property rights for a large proportion of the scholarly record is held by publishers, so a majority of journal articles are behind paywalls and unavailable to most people. As a result some readers are encouraged to use pirate websites such as Sci-Hub to access them, a practice that is alternately regarded as criminal and unethical or as a justified act of civil disobedience. This article considers both the efficacy and ethics of piracy, placing ‘guerrilla open access’ within a longer history of piracy and access to knowledge. By doing so, it is shown that piracy is an inevitable part of the intellectual landscape that can render the current intellectual property regime irrelevant. If we wish to actively construct a true scholarly commons, open access emerges as a contender for moving beyond proprietary forms of commodifying scholarly knowledge towards the creation of an open scholarly communication system that is fit for purpose.