Flock Exposed - Any Privacy Left
You've probably heard the pitch: you have no right to privacy when you're standing, or driving, on a public street.
That is the entire legal foundation Flock and the agencies that deploy its cameras stand on - if you can be seen in public, the thinking goes, there is nothing left to protect. It is a simple argument, and for decades it was basically correct.
But a recent Supreme Court ruling, building on something legal scholars call the mosaic theory, is starting to challenge that assumption at its foundation. The idea is straightforward once you hear it: watching one moment of your public life reveals almost nothing, but stitching together thousands of those moments - every drive, every day, for months or years - starts to reveal your whole life: where you worship, who you visit, what doctor you see, where your kids go to school. Courts are increasingly asking whether that complete picture deserves protection the Constitution never denied you, even if each individual piece was technically "public." The case examples below trace exactly how that argument has developed, from its origins through the Supreme Court's own recent rulings, and how it's now colliding directly with lawsuits over Flock's camera networks specifically.
The legal fight - now reaching the U.S. Supreme Court's own doctrine - over whether stitching together enough public sightings of you amounts to a "search" the Constitution is supposed to guard against.
The old answer was no: anything visible from a public street was fair game, under cases like Katz v. United States and New York v. Class. That rule still covers a single glance. It does not survive what the Supreme Court did in 2018, and it is now facing a direct challenge in the federal courts over Flock's own camera networks specifically. In fairness, that challenge is still unresolved and the technology's defenders have real legal arguments of their own - this page lays out both sides.
1. The Supreme Court created the modern rule: enough data becomes a search
In Carpenter v. United States, 585 U.S. 296 (2018), the Court held that pulling seven days of a person's cell-phone location history was a "search" requiring a warrant - specifically because of how detailed and effortlessly compiled that record was. Handing your data to a company in the ordinary course of life, the Court said, does not by itself waive your privacy in it.
Source: Congressional Research Service (Congress.gov IF13068); Carpenter v. United States, 585 U.S. 296 (2018).
2. The "mosaic theory," explained the way courts explain it
Courts now widely apply what's called the mosaic theory: a single tracked moment tells you almost nothing, but enough tracked moments, stacked together, tell you everything - where someone worships, who they visit, what doctor they see, where their kids go to school. The color of one stone in a mosaic is meaningless. Step back far enough and the whole picture becomes plain. That whole picture is what the Fourth Amendment protects, even when every individual piece was "public."
Source: Reason/Volokh Conspiracy, analysis of state supreme court ALPR ruling, 2020.
3. A state supreme court applied this exact reasoning to license plate readers
In Commonwealth v. McCarthy, Massachusetts's highest court held that a person does have a reasonable "expectation of privacy in the whole of his public movements" - an interest ALPR networks are capable of violating, even though the court found this particular defendant's data hadn't been used pervasively enough to cross that line yet.
Source: Harvard Law Review, Commonwealth v. McCarthy case note.
4. A federal court has already warned that a Flock network specifically could cross this line
In United States v. Jackson (District of Kansas), the court upheld the use of Wichita's roughly 160-camera Flock network in that case, but it did not stop there - it warned that "the more widespread and pervasive deployment of Flock cameras . . . could eventually rise to the level of systemic and continuous tracking" that Carpenter says requires a warrant. A federal judge has already put Flock-style networks on notice, by name.
Source: United States v. Jackson, D. Kan.; case analysis citing Flock deployment figures.
5. "It's just a plate scan" is losing ground on the technical facts, not just the law
As camera density in an area rises, the gap between one camera's sighting and the next shrinks - and individual snapshots start to function as a continuous trail. Researchers already use ALPR data with reinforcement-learning models to reconstruct a vehicle's complete path between sensors, for purposes that have nothing to do with law enforcement. The capability for GPS-equivalent tracking of your car already exists and is already in use.
Source: Independent Institute, "License Plate Reader Baton Passing," 2026.
6. Legal scholars say this fight is intensifying, not settling down
The mosaic theory traces back to United States v. Jones (2012), where the D.C. Circuit introduced the aggregation-based approach Professor Orin Kerr named the "mosaic theory" of the Fourth Amendment. Carpenter has been called a landmark privacy decision likely to shape constitutional privacy law for a generation. This question is not resolved - it is actively being fought in courts across the country right now.
Source: Texas Law Review, "The Mosaic Theory's Two Steps: Surveying Carpenter in the Lower Courts."
7. The Supreme Court just extended this reasoning again, in a June 2026 ruling legal analysts say points straight at ALPR networks - though the ruling has real limits
In Chatrie v. United States, decided June 29, 2026, the Supreme Court ruled 6-3 (Justice Kagan writing for the majority, Justice Barrett dissenting) that police conducted a Fourth Amendment search when they obtained a suspect's cell-phone location data through a geofence warrant, after investigators identified robbery suspect Okello Chatrie by ordering Google to hand over Location History data for every phone within 150 meters of a Virginia credit union around the time of the crime. Just as important as the holding is the reasoning: the Court rejected the argument that a search is fine simply because investigators only pulled a narrow, time-limited slice of a much larger dataset. Once the Fourth Amendment applies, the majority held, it doesn't matter how small a bite investigators took out of an all-encompassing database - directly undercutting the main defense governments have used for Flock-style camera networks. Legal analysts covering the decision flagged automated license plate readers as likely to be the next major battleground for this same fight.
To be fair to the other side, Chatrie is a cell-phone geofence case, not an ALPR case, and stationary roadside cameras sit on a different, older legal branch of precedent going back to United States v. Knotts (1983), which held that a person driving on public roads has no reasonable expectation of privacy in movements from one place to another. Nothing in Chatrie forces any city to shut off a single Flock camera, and defenders of these networks are expected to keep leaning on that distinction. Chatrie removed one legal argument its defenders had been using - it did not decide the ALPR question itself, and that question remains genuinely open.
Source: SCOTUSblog, "The Supreme Court expands protections for digital data - now what?," August 2026; The Auto Wire, "Supreme Court Ruling Could Reshape Flock License Plate Camera Lawsuits," July 6, 2026; Chatrie v. United States, decided June 29, 2026.
8. That Supreme Court ruling landed in the middle of a live federal case over a Flock network itself: Schmidt v. City of Norfolk
Lee Schmidt and Crystal Arrington sued Norfolk, Virginia in October 2024, with backing from the Institute for Justice, arguing that the city's roughly 175-camera Flock network - which builds a "Vehicle Fingerprint" cataloging a car's color, make, body style, and even bumper stickers, and holds the data for 21 days, the maximum allowed under Virginia law - amounts to a warrantless dragnet search of their daily movements. In January 2026, a federal judge in the Eastern District of Virginia granted summary judgment for the city, reasoning that 21 days and 175 cameras didn't add up to the kind of exhaustive surveillance Carpenter was concerned with. Schmidt and Arrington appealed to the Fourth Circuit, where the case (No. 26-1227) drew amicus briefs from the ACLU, ACLU of Virginia, and Electronic Frontier Foundation on one side, and from South Carolina leading fifteen other states plus the District of Columbia defending Norfolk on the other. The states' brief leaned heavily on a 2024 Fourth Circuit panel ruling that geofence data collection wasn't a search at all - but that panel ruling was vacated when the full Fourth Circuit took the case en banc, and the en banc ruling that replaced it was itself wiped out by the Supreme Court's Chatrie decision on June 29, 2026. In other words, the precedent Norfolk's defenders relied on to win at the district court no longer exists in any form, and the case is currently pending at the Fourth Circuit with fresh Supreme Court authority cutting against the network's defenders - though it bears repeating that Norfolk already won once at the district court, and fifteen states plus the District of Columbia are actively defending the network's legality.
Source: The Auto Wire, "Supreme Court Ruling Could Reshape Flock License Plate Camera Lawsuits," July 6, 2026; Institute for Justice, case page on Norfolk surveillance; Cato Institute amicus brief summary.
9. San Jose is being sued the same way, over an even larger network with year-long retention - but the case rests on state, not federal, law
In November 2025, the ACLU of Northern California and the Electronic Frontier Foundation sued San Jose, California in Santa Clara County Superior Court on behalf of the California chapter of the Council on American-Islamic Relations (CAIR-CA) and the Services, Immigrant Rights and Education Network (SIREN). The suit challenges San Jose's roughly 500-camera Flock network, which retains location data for a full year - far longer than most agencies - creating what the lawsuit calls a surveillance system that is "especially pervasive in both time and space." The complaint notes cameras are positioned near immigration centers, clinics, and places of worship, and argues the retrospective, warrantless searching of that year-long archive violates the California Constitution's ban on unreasonable searches, independent of any federal Fourth Amendment question. The lawsuit seeks a court order requiring San Jose to get a warrant before searching its ALPR database or letting outside agencies do so.
In fairness, this claim is built entirely on the California state constitution, not the federal Fourth Amendment. That matters both ways: California's constitutional privacy protections are broader than federal law in some respects, so the plaintiffs may not need a Carpenter-style federal win to succeed. But a ruling here, even a win, would only bind California and would not set the kind of nationwide precedent a Fourth Circuit or Supreme Court decision in the Norfolk case would - and a loss in San Jose would not necessarily weaken the separate federal case in Norfolk either, since the two run on entirely separate legal tracks.
Source: KQED, "Civil Liberties Groups Sue San Jose Over License Plate Reader Use," November 18, 2025; CAIR-CA press release, November 18, 2025; 404 Media, "ACLU and EFF Sue a City Blanketed With Flock Surveillance Cameras."
10. A separate statewide class action targets Flock directly, not just the cities that buy its cameras
On February 26, 2026, the law firm Gibbs Mura, together with Milberg PLLC, filed a class action against Flock Safety itself in San Francisco Superior Court, alleging the company violated California's ALPR Privacy Act (SB 34, passed in 2015) by sharing license plate data with out-of-state and federal agencies, in addition to violations of the state's Unfair Competition Law and constitutional privacy protections. An amended complaint was filed April 3, 2026. Unlike the Norfolk and San Jose cases, which challenge a city's use of the technology, this lawsuit goes after the vendor's own data-sharing practices directly. Like the San Jose case, this is a California state-law claim and would not by itself set nationwide precedent.
Source: BusinessWire, "Flock License Plate Cameras Face Class Action Lawsuit by Gibbs Mura, A Law Group"; Class Law Group, Flock Safety License Plate Reader Cameras Lawsuit page.
11. Westchester County, New York faces a 1.6-billion-scan lawsuit invoking the state constitution
On June 9, 2026, four Westchester County motorists filed a proposed class action - Umemoto v. Westchester County Police Department - in New York state court, represented by the NYCLU, the Policing Project at NYU School of Law, the Knight First Amendment Institute at Columbia University, and the law firm Freshfields. The suit alleges the county's roughly 575 to 600 Flock cameras have amassed approximately 1.6 billion license-plate reads, held for at least two years and shared with more than fifty outside agencies, including U.S. Immigration and Customs Enforcement, the FBI, and the DEA - without the county ever getting proper authorization to launch the program in the first place. The complaint asks the court to declare the network unconstitutional under the New York State Constitution and to order an injunction halting the program's operation while the case proceeds. As with San Jose, this claim rests on New York's state constitution rather than the federal Fourth Amendment, so its reach would be limited to New York if successful.
Source: Associated Press, "Motorists sue Westchester County over 1.6 billion license plate scans," June 9-12, 2026; RecordingLaw.com, "Westchester License Plate Reader Lawsuit: 1.6 Billion Scans (2026)."
12. A Washington state appellate court reached the opposite result on a single scan - illustrating exactly where the legal line currently sits
In State v. Simonson (Wash. Ct. App., decided January 29, 2026), the Washington Court of Appeals held that a single Flock camera image captured on a public roadway did not implicate constitutional privacy protections. Legal commentators note this ruling and Norfolk's original district-court win represent one side of a genuine split, with the San Jose and Westchester lawsuits, and now Chatrie, pushing the opposite direction - the question of aggregation and duration, not a single snapshot, is where these cases actually turn. This ruling stands as a real, current precedent on the technology's side, not just a hypothetical argument - it is the law in Washington today.
Source: The Eye That Never Blinks: Flock and ALPR (Moro Lawyers legal analysis); State v. Simonson, Wash. Ct. App., January 29, 2026.
13. A federal appeals court struck down a citywide aerial surveillance program on the exact same "mosaic" logic
In Leaders of a Beautiful Struggle v. Baltimore Police Department, the Fourth Circuit Court of Appeals, sitting en banc, reviewed Baltimore's Aerial Investigation Research program, which flew surveillance planes over the city up to twelve hours a day, capturing the outdoor movements of nearly all 600,000 residents. The full court held that accessing this data, in the aggregate, allowed police to deduce the whole of a person's movements, and that this itself is a search, and its warrantless operation violates the Fourth Amendment. This is a real circuit-level win squarely on the mosaic theory, not just a district court decision, and it directly undercuts the "public means unprotected" defense: every one of those flights only captured people already out in public view, and the court still called the aggregate a warrantless search.
Source: Fourth Circuit Court of Appeals, Leaders of a Beautiful Struggle v. Baltimore Police Department, decided en banc June 24, 2021; Harvard Law Review case summary.
14. A Virginia court ruled the Flock system itself, not just a single scan, is a search requiring a warrant
In Commonwealth v. Bell, a Norfolk Circuit Court judge found that the collection and storage of license plate and location information by the Flock system constitutes a search within the meaning of the Fourth Amendment and should require a warrant. This is a direct rejection of Flock's own defense that a single plate photograph is no different than an officer's eyeballs on a public street - the court looked at the system as a whole, the way Carpenter and the mosaic theory frame the question, and found it crosses the line.
Source: Commonwealth v. Bell, 113 Va. Cir. 316 (2024); Virginia Lawyers Weekly.
15. A second Virginia court followed suit and threw out the evidence entirely
Building on Bell, a Virginia court in Commonwealth v. Church relied on that precedent and held that a warrantless search of the Flock system violated the Fourth Amendment, suppressing the ALPR evidence the prosecution was relying on. Two separate Virginia rulings have now reached the same conclusion: querying a Flock database is a search, and doing it without a warrant can get the evidence thrown out of court.
Source: Commonwealth v. Church, Va. Ct. App., 0737-25-1 (Oct. 14, 2025); Electronic Frontier Foundation.
16. Before it went to trial, the Norfolk case survived an early legal test - a real, citable victory even though the city later won at trial
Months before the district court's final January 2026 ruling in favor of Norfolk, that same lawsuit cleared an earlier hurdle. On February 5, 2025, Chief Judge Mark Davis denied the city's motion to dismiss the case outright, reasoning that the plaintiffs sufficiently alleged a violation of their subjective and reasonable objective expectations of privacy, and plausibly alleged that a search had occurred. In that ruling, the court leaned on Carpenter v. United States to find the claim legally viable enough to proceed to trial.
In fairness, this was only a preliminary win, not a final ruling on the merits, and it does not cancel out the fact that the same judge ultimately ruled for Norfolk at trial eleven months later. But it stands as a real, citable moment where a federal court agreed that a claim like this is legally serious enough to survive a motion to dismiss - and that ruling is still good law, un-reversed, even though the plaintiffs went on to lose the later trial (a loss now under appeal at the Fourth Circuit).
Source: Schmidt v. City of Norfolk, No. 2:24cv621, 2025 WL 410080 (E.D. Va. Feb. 5, 2025); Institute for Justice; Techdirt.
Where This Leaves Us
No court has yet ruled that ALPR networks categorically violate the Fourth Amendment, and it would be unfair to claim otherwise. But every court that has looked closely has said the same thing in different words: one scan on a public road is not a search - but enough scans, over enough time, covering enough of a person's daily life, can become one. A federal appeals court has already struck down a citywide aerial surveillance program on this exact reasoning, two separate Virginia courts have ruled that querying the Flock system itself is a search requiring a warrant, and a federal court in Kansas has already named Flock specifically as capable of crossing that line. The Supreme Court's most recent digital-privacy ruling in Chatrie has knocked out one of the legal arguments Norfolk and other cities have used to defend their networks in court, and even the Norfolk case itself, before it was ultimately decided for the city at trial, first survived a motion to dismiss on the strength of these same privacy arguments - though Norfolk did win at trial, fifteen states plus the District of Columbia are actively defending these networks, and a separate Washington appellate court has ruled the other way entirely. With Schmidt v. City of Norfolk now pending at the Fourth Circuit, San Jose and Westchester County facing their own active state-law lawsuits over far larger and longer-retained databases, and a direct class action targeting Flock's own data-sharing practices, this issue is genuinely unresolved and being actively litigated in courtrooms across the country on both sides. The outcome will decide whether a "public road" pitch can keep justifying a system that courts have already said can require a warrant once it's networked and retained at scale - or whether the technology's defenders are right that a camera on a pole is fundamentally different from a phone in your pocket.
This page will be updated as more factual sources become available.