This Article focuses on an unappreciated and significant aspect of the debate over property rules in the technology law context. In particular, it argues that the classic justification for legal entitlements protected by a property rule - i.e., a right to injunctive relief - depends on the ability to define and enforce property rights effectively. In the case of many technology markets, the inability to tailor injunctive relief so that it protects only the underlying right rather than also enjoining noninfringing conduct provides a powerful basis for using a liability rule (i.e., awarding the relevant damages to the plaintiff) instead of a property rule. Notably, where injunctive relief cannot be confined to protecting the underlying right,...