This Essay argues that the “subjective expectation of privacy” test from Katz v United States is a phantom doctrine. The test exists on paper but has no impact on outcomes. An empirical study of cases decided in 2012 indicates that the majority of judicial opinions applying Katz do not even mention the subjectiveexpectations test; opinions that mention the test usually do not apply it; and even when courts apply it, the test makes no difference to the results.
The subjective test acts as a phantom doctrine because of an overlooked doctrinal shift. A close reading of Justice John Marshall Harlan’s Katz concurrence suggests that the subjective test was originally intended to restate the holdings of the Supreme Court’s cases on invited exposure. Under those cases, an individual waives his Fourth Amendment rights by inviting others to observe his protected Fourth Amendment spaces. After Katz, however, the Supreme Court misunderstood this original design and recast those holdings as part of the objective test instead of the subjective test. This doctrinal shift quietly eliminated the role of the subjective test. The Supreme Court should abolish the subjective-expectations test to clarify and simplify Fourth Amendment law.