## Facts

- Baltimore police implemented a pilot wide-area aerial surveillance program using aircraft-mounted cameras that captured continuous imagery of most of the city for many hours per day, weather permitting.
- Individuals and vehicles appeared as small “dots,” but analysts could follow those dots over time and correlate the imagery with other data sources to identify people and reconstruct movements.
- Imagery was retained for 45 days, with certain reports and associated imagery retained longer for investigative and legal needs.
- Plaintiffs (a community organization and two individuals) brought a 42 U.S.C. § 1983 action challenging warrantless access to and use of the imagery as violating the Fourth Amendment, also raising related First Amendment concerns.
- The district court denied a temporary restraining order and preliminary injunction, reasoning the program resembled traditional aerial observation and did not intrude on a reasonable expectation of privacy.
- A divided Fourth Circuit panel affirmed; the full court granted rehearing en banc, vacated the panel decision, and heard the case.
- Although the police department later discontinued the program, it retained at least some collected data, and the dispute over access to that data remained ongoing.

## Issues

1. Whether warrantless access to and use of the aerial-imagery dataset that enables reconstruction of individuals’ movements over time constitutes a Fourth Amendment “search.”
2. Whether plaintiffs satisfied the requirements for a preliminary injunction (likelihood of success, irreparable harm, balance of equities, and public interest).
3. Whether discontinuation of the program mooted the case when the government still possessed and could access previously collected data.

## Decision

- The en banc court reversed the denial of a preliminary injunction and remanded with instructions to enter a preliminary injunction barring warrantless access to the aerial surveillance data.
- The court held that police access to and use of the program’s aggregated imagery to reconstruct the whole of an individual’s movements constitutes a Fourth Amendment search.
- The court held the case was not moot because retained data and potential access to it kept the controversy live.
- The court concluded plaintiffs showed a likelihood of success on the merits and that the remaining preliminary-injunction factors favored relief.

## Legal Principles

- Government acquisition or use of data that enables retrospective reconstruction of the whole of a person’s movements over time can be a Fourth Amendment search, even if each discrete observation occurs in public.
- The Fourth Amendment analysis may focus on what long-term, aggregated access permits the government to infer, not solely on the content of any single snapshot.
- City-wide, persistent aerial collection that supports retrospective tracking is materially different from brief, targeted aerial observations previously upheld for specific locations.
- Alleged ongoing unconstitutional searches or continued government access to previously collected surveillance data can support prospective injunctive relief and defeat mootness where the dispute remains live.
- For preliminary injunctions in constitutional cases, a likely Fourth Amendment violation supports a finding of irreparable harm, and the public interest favors law-enforcement practices consistent with constitutional limits.

## Conclusion

The en banc Fourth Circuit treated Baltimore’s wide-area aerial surveillance, when used to reconstruct individuals’ movement histories, as a Fourth Amendment search and required preliminary injunctive relief against warrantless access to the collected data, notwithstanding the program’s discontinuation because retained data kept the dispute active.


Leaders of a Beautiful Struggle v. Balt. Police Dep’t, 2 F.4th 330 (4th Cir. 2021) (en banc)