Final Version, "Data Scanning and the Fourth Amendment"

Key Takeaways

• Article links search scope to filter settings, not database size
• Analyzes geofence warrants, reverse keyword searches, tower dumps
• Supreme Court will hear United States v. Chatrie in April
• Decision could unify split on digital data scans
• Impacts law enforcement practices and privacy protections

Summary

Law professor Kevin Volokh published the final version of his article "Data Scanning and the Fourth Amendment" in the Boston College Law Review, arguing that the scope of a Fourth Amendment search should be measured by filter settings rather than database size. The piece examines geofence warrants, reverse keyword searches, tower dumps, and AI queries, emphasizing what information is exposed to human observation. The Supreme Court has agreed to hear United States v. Chatrie, a geofence‑warrant case that could resolve the current split on data‑scan searches. Oral arguments are set for April 27, positioning the article’s framework for potential judicial adoption.

Pulse Analysis

The Fourth Amendment’s application to modern digital investigations has become a flashpoint as courts grapple with the definition of a "search" in the age of massive data repositories. Traditional analysis focused on the size of the database or the volume of raw data processed, creating a patchwork of rulings that left law‑enforcement agencies uncertain about the legality of broad data‑scanning techniques. By shifting the focus to the filter settings that determine what information is actually presented to an officer, scholars aim to provide a clearer, more consistent standard that aligns with constitutional oversight.

Volokh’s article advances this filter‑centric framework, contending that the critical question is not how much data passes through a system but what the output reveals to human eyes. This perspective directly addresses contentious practices such as geofence warrants, where agencies sweep all location data within a defined area, and reverse keyword searches that flag records matching specific terms. By evaluating the exposure of actionable intelligence rather than raw data volume, the proposed approach could narrow the scope of permissible searches, requiring warrants for broader sweeps while preserving targeted investigations.

The Supreme Court’s upcoming hearing in United States v. Chatrie offers a real‑time test of these theories. A ruling that adopts the filter‑setting analysis would harmonize divergent circuit opinions and set a national benchmark for digital search warrants. Such a decision would reverberate across law‑enforcement, tech, and privacy sectors, influencing how agencies design data‑collection tools, how companies store user information, and how courts balance security with constitutional rights. The outcome will likely shape the legal landscape for digital surveillance for years to come.