This Article considers how Fourth Amendment law should adapt to the global nature of Internet surveillance. It focuses on two types of problems not yet addressed by courts. First, the Supreme Court’s decision in United States v. Verdugo-Urquidez prompts several puzzles about how the Fourth Amendment treats monitoring on a worldwide network where many lack Fourth Amendment rights. For example, can online contacts help create those rights? What if the government mistakenly believes that a target lacks Fourth Amendment rights? How does the law apply to monitoring of communications between those who have and those who lack Fourth Amendment rights? The second category of problems follows from different standards of reasonableness that apply outside the United States and at the international border. Does the border search exception apply to purely electronic transmission? And if reasonableness varies by location, is the relevant location the search, the seizure, or the physical person?

This Article explores and answers these questions using equilibrium-adjustment, a method of applying the Fourth Amendment to technological changes to maintain the preexisting balance of constitutional protection. Fourth Amendment doctrine is heavily territorial: connections to the United States impact the scope or existence of constitutional protection. This Article aims to adapt existing principles for the transition from a domestic, physical environment to a global, networked world. It concludes that courts should reject online contacts as a basis for Fourth Amendment protection; allow monitoring when the government wrongly but reasonably believes that a target lacks Fourth Amendment rights; and limit monitoring between those who have and those who lack Fourth Amendment rights. It also contends that the border search exception should not apply to electronic transmission and that reasonableness should follow the location of data seizure. Taken together, the solutions offered in this Article provide a set of Fourth Amendment rules tailored to the reality of global computer networks.