It seems, once again, that intellectual property law is shifting beneath our feet. As Robert Merges put it a decade ago, if IP were a city, then the old city centre is today ‘surrounded by new buildings and new neighbourhoods, knots of urban growth, budding in every direction, far off into the distance’.1 That old city centre was built during the nineteenth-century age of possessive individualism.2 Ideologies of the romantic author and sole inventor helped erect the city’s foundational principle that one deserves ownership in the products of mental labour.3 Yet, in the early twentieth century, US Supreme Court Justice Louis Brandeis could still write that ‘the general rule of law is, that the noblest of human production – knowledge, truths ascertained, conceptions, and ideas – become, after voluntary communication to others, free as the air to common use’.4 A century later, that general rule rings less true.5 Investment-driven rights, and investment-driven extensions to old rights, have helped expand the city’s boundaries. What started out as a small cadre of related rights, sui generis rights, and quasi-IP rights now contribute to an urban sprawl of new neighbourhoods spreading as far as the eye can see. New denizens – the trivially creative and insignificantly innovative goods explored in this volume – now are protected inside the city’s walls. What was the city of Intellectual Property has become the city of Investment Property.

This chapter introduces the concept of IP accidents. Infringements are accidental when, ex ante, the user could only perceive a risk of infringement. IP accidents are a highly pervasive, yet underacknowledged, problem in IP law. In order to achieve the correct balance between incentives and access, IP law must treat accidental infringements differently from other types of infringement.

IP accidents were a relatively small problem in the nineteenth century. Strict liability was an appropriate liability rule at this time because avoiding accidents was comparatively easy. However, due to changes in technology and the legal system, the volume of IP accident litigation has grown during the twentieth and twenty-first centuries. Just as the tort of negligence was created during the Industrial Revoluion to handle the increase in accidental personal injury litigation, society should adopt a negligence principle to govern IP accidents in the Information Age.

This chapter provides a brief overview of the book’s main themes and arguments. IP accidents should be governed by a negligence liability rule for reasons of efficiency, equity, and fairness.

Negligence is a more efficient liability rule than strict liability. Under a negligence liability rule, all parties (owners and users) will be incentivised to adopt reasonable, cost-justified, and non-excessive care to avoid infringements. This will minimise the overall social cost imposed by accidents. At the same time, introducing a negligence liability rule will distribute creative risk more equitably leading to a more just and attractive culture.

What does the recognition of IP accidents teach lawyers about the relationship of IP to property and tort? This chapter argues that IP law is best understood as part of property and tort law simultaneously. While IP rights are proprietary in nature, infringement of those rights is tortious. While IP law is primarily about assigning rights in intangibles and defining their scope, 'intellectual tort' refers to the legal rules that determine when an infringer ought to be held responsible for their infringements.