This chapter provides a comprehensive review of the current state of Australian online intermediary liability law across different doctrines. Different doctrines in Australian law employ a range of different tests for determining when an actor will be liable for the actions of a third party. So far, these primarily include cases brought under the laws of defamation, racial vilification, misleading and deceptive conduct, contempt of court, and copyright. These bodies of law are conceptually different and derive from different historical contexts, and the courts have generally applied them in isolation. The chapter shows that the basis on which third parties are liable for the actions of individuals online is confusing and, viewed as a whole, largely incoherent. The chapter shows how the principle limiting devices of liability across all of these schemes—intention, passivity, and knowledge—are ineffective in articulating a clear distinction for circumstances in which intermediaries will not be held liable. The result is a great deal of uncertainty. It is argued here that intermediary liability law should develop by focusing on the concept of responsibility, and that existing principles in tort jurisprudence and theory can help to guide and unify the different standards for liability.