Disproportionate by Default: The Reason Behind the Reason Field

Last week, the haveibeenflocked.com system ingested its 100 millionth record of a Flock search. I’ve been vocal about the lack of transparency and how widespread abuse appears to be, even based on the limited information we have. But what if we were to ignore that? What if we look at the system and pretend that it is used as intended? The logs tell a story that is perhaps even more disturbing: police will examine your long-term location history for any reason or no reason at all.

Location histories and the Fourth Amendment

The most pertinent discussion, or lack thereof, can be found in the lower court’s holding in Carpenter v. United States, which SCOTUS described as:

The Court declines to say whether there is any sufficiently limited period of time “for which the Government may obtain an individual’s historical [location information] free from Fourth Amendment scrutiny.” But then it tells us that access to seven days’ worth of information does trigger Fourth Amendment scrutiny […] Why seven days instead of ten or three or one? And in what possible sense did the government “search” five days’ worth of location information it was never even sent? We do not know.

There was clearly some concern at the Supreme Court and among the parties regarding the length of the location history. The Supreme Court’s holding in Carpenter was narrow and it declined to address the confusion, writing in a footnote that “[i]t is sufficient for our purposes today to hold that accessing seven days of CSLI constitutes a Fourth Amendment search.”

Whether a cut-off exists under which retrieving location history data would no longer be a Fourth Amendment search, or where that cut-off would be, were not questions addressed by the Court, but in Carpenter, seven days of location history was enough.

Although Flock downplays the completeness of its data and the general usefulness and accuracy of its “critical tool” when it comes to defending it in the face of Carpenter, a federal court in Virginia has already found that 176 Flock cameras in Norfolk, VA “plausibly violate” the Fourth Amendment.^[1]

Courts have not yet addressed Flock’s actual network density, suspected to include more than a quarter million cameras.

Disproportionate by Default

Flock’s lookup tool, which is used for exact plate searches across the state- and nationwide networks, offers users limited options for the length of the requested location history: 1 day, 7 days, or 30 days.

Its “search” tool, which can search for partial plates, vehicle characteristics, and use “freeform” text queries, is not restricted in that way. It can do both longer and shorter searches.

It is unclear whether there is a default setting for either, what the default setting is if there is one, or who would configure the default setting. I do not recall ever seeing an ALPR policy or city council minutes that discuss this.

Examining per-state data for lookups^[2] yields the following results:

Considering this chart, a per-state or per-organization default setting seems unlikely, however, the uniformity of location history lengths has changed over time:

The high uniformity suggests a system-wide default that users are accepting. The sudden change in mid-2025, where users begin choosing different lengths for location history, may be part of the same systemwide changes that appeared in Santa Cruz in August.

The suddenness of the shift in uniformity suggests that Flock switched to a 7-day default around that time and users are less accepting of that default than they were of the earlier, 30-day default.

Regardless of any default, individual users still passively or actively choose to retrieve these histories without much apparent concern for proportionality. A seven- or thirty-day location history because an officer can’t be bothered to select a more appropriate menu option strays far from the reasonableness the Fourth Amendment demands.

Finally, for all searches in our database that have timeframe information, the average length of location histories retrieved is 18 days, 5 hours, 39 minutes. That includes “search” queries as well as “lookup” and other types of queries.

Before the Dropdown

But why are users pulling these long-term histories? “Every search must be accompanied by a reason.” Before switching to dropdowns in January 2026, Flock users were free to enter their own reasons. Although they often did not—beyond “inv” or “sus”—the reasons that were entered do provide a glimpse into what might trigger long-term lookups of location histories.

• Suspicious Person on Campus: 30 days
• stranger danger: 30 days
• Suspicious Auto (bullet holes): 30 days^[3]
• fishing violation: 33 days, 1 hour
• h&r vehicle: 217 days
• lowes theft: 366 days

It’s hard to come up with a reason why, or how this would contribute to the investigations described.

Dropdown Reasons

Maybe Flock’s new reason dropdown will live up to the marketing hype and provide more transparency. To be clear: these are the reasons that someone, somewhere, found acceptable enough as a reason for location history retrieval.

Traffic Infractions and DUIs

Through the dropdown, the Texas Department of Public Safety states it frequently uses the system for “Traffic Infraction - Criminal Justice Purpose.”

Although we can’t know what “Traffic Infraction - Criminal Justice Purpose” actually means, we know that most traffic infractions are short-lived; where someone had lunch last week has little probative value in cases where someone failed to stop at a stop sign.

Regardless, the vast majority of Texas DPS’s traffic-related location history retrievals exceeded the seven-day threshold the Supreme Court found implicated the Fourth Amendment in Carpenter.

DPS pulled histories exceeding 250 days in several cases.

The California Highway Patrol similarly uses Flock for DUI investigations.

California, of course, has much stricter controls on ALPRs and the Ninth Circuit tends to be more privacy-friendly than its counterparts elsewhere in the country. This may explain why CHP’s use appears much more restrained than Texas’.

But that restraint is relative—CHP still retrieved location histories for seven or more days in more than half of the DUI investigations where it used Flock. What evidentiary value this could possibly have is anyone’s guess.

Welfare Checks

Perhaps even more concerning is the Harris County, Texas, Sheriff’s Office use of Flock for welfare checks.

Welfare checks are not criminal investigations, and they are not generally triggered by accusations of any crime. They are also not the same as missing persons cases. They can range from neighborly concern to someone actively threatening suicide. In these cases, there may be a clear defense for the legality of retrieving a person’s current location to prevent harm, but the government does not need to know where they’ve previously been.

Yet here too, for more than half of “Welfare Checks” the Harris County, Texas, Sheriff’s Office retrieves location histories of seven days or more: a length the Supreme Court found sufficient to trigger the Fourth Amendment.

And they’re doing it in cases where there is no criminal investigation, and no evidence of a crime.

The Reason Behind the Reason

The implications of some of these long-term searches are concerning.

While a DUI suspect’s long-term location history seems like a mostly pointless violation of rights, what possible conclusion could someone draw from a shoplifter’s vehicle’s location a year ago? How does knowing where the “suspicious person on campus” has been decrease the suspiciousness of his actions today?

A 30-day history will tell you at a glance the general area where a person lives and works. That reveals information about their socio-economic status and, in many cases to a degree of statistical certainty, their race. Maybe the reasoning is that a person who lives a wealthy suburb is less “suspicious” when they’re walking around campus, while someone from the wrong side of the tracks presents more “stranger danger.”

Whether it’s laziness or active profiling, the system is designed to make disproportionate surveillance the path of least resistance. Flock could have defaulted to 1 day. They could have required more justification for longer histories. Instead, they built a system where retrieving a month of someone’s movements requires less thought than ordering a cup of coffee.

The Fourth Amendment doesn’t distinguish between malice and indifference. Neither should we.