Abstract: The Fourth Amendment is generally seen as a procedural provision blind to a defendant’s conduct in a given case, distinguished on that very ground from the Supreme Court’s frequently moralistic assessment of conduct in its due process privacy caselaw. Yet ever since the Court recentered Fourth Amendment protections around an individual’s reasonable expectations of privacy, it has consistently tied those protections to the nature and, specifically, the social value of the activities involved. As in its substantive due process cases, the Court frequently allots Fourth Amendment privacy interests based on its moral evaluation of private acts, privileging conventional social goods like domesticity, romantic relations, and meaningful emotional bonds. And in some cases—most notably those involving aerial surveillance, home visitors, and drug testing—the Court has adopted an expressly retrospective analysis, tying Fourth Amendment rights to a defendant’s actual conduct at the time of a search. This unrecognized strain of moralism in the Fourth Amendment is a troubling development, unmoored from the Amendment’s text, hostile to its well-documented history, and obstructive of its practical operation in regulating police abuses. Not least, that moralistic approach upends prevailing understandings of privacy, as a refuge from the pressures and expectations of society. Especially in the electronic age, as digital technologies vastly expand the police’s ability to parse categories of private data, the Court must cabin its moralistic turn, restoring a richer view of Fourth Amendment values as encompassing individualistic and unorthodox pursuits. This Article identifies two immediate steps for moving forward: renouncing the Court’s privileging of “intimate” over impersonal conduct and reconsidering the controversial binary-search doctrine gleaned from the Court’s drug-testing cases. More fundamentally, it joins an ongoing debate about the adequacy of the Court’s privacy-based Fourth Amendment framework, suggesting both the importance and the difficulty of restoring a Fourth Amendment attuned to liberal values of individualism and moral autonomy. Finally, this Article addresses what the surprising rise of Fourth Amendment moralism suggests about constitutional privacy rights more broadly. Belying the value of privacy as a sanctuary from social judgment, the Court’s persistently moralistic jurisprudence challenges the extent to which our Constitution has ever protected, and perhaps can ever protect, a robust right of “privacy” as such.