Lawsuit Filed Challenging Constitutionality Of Vast Network Of Illinois License Plate Readers

This lawsuit might be a long shot, but it’s not completely a foregone conclusion at this point. The state of Illinois has tougher privacy laws than most states, which may factor into the judge’s decision. On the other hand, this lawsuit — filed by two Illinois residents with the assistance of the Liberty Justice Center — has been filed in federal court, where assumptions about expectations of privacy won’t necessarily be quite as affected by state law stipulations.

What will help this lawsuit along is just how many automatic license plate readers the state has installed, as well as how many records of people’s movements it has on hand at any given moment. Reason’s Patrick McDonald has the stats on that, and those show this form of surveillance is pretty pervasive, even if it only involves plate/location information.

Illinois State Police received a $12.5 million state grant in 2021 to install cameras, which was more than doubled in June 2022 when Pritzker extended the act, granting up to $20 million in additional funding. As of publishing time, the Illinois Department of Transportation has purchased 652 license plate cameras, of which 340 are installed in Cook County, which includes Chicago.

According to the ISP’s dashboard, in the past month, the system has recorded over 215 million “detections” (when a camera captures a digital image of a license plate) and over 1. 4 million “hits” (when a captured license plate matches a plate on the state police’s “Hot List,” which includes the license plate numbers of stolen vehicles and wanted subjects). Annually, the system records over 1.5 billion detections—more than 100 times the state’s population. 

That’s just in Cook County. There are others scattered across the state, but the focal point of ALPR deployment is the Chicago metro area.

It’s the sheer number of readers and total number of “detections” that may sway the court to consider ALPRs more akin to always-on surveillance than just the privacy price to be paid for enjoying the use of public roads.

“Public” is the key word. Areas accessible by anyone at any time (most public roads) aren’t generally treated as areas worthy of a reasonable expectation of privacy. On the other hand, most people aren’t sitting on public roads capturing photos of every car that passes by 24/7.

In total, it seems like a privacy violation. Running a plate against an ALPR database could give the government a pretty complete picture of a person’s movements. But even so, courts have often rationalized that if a single ALPR snapshot isn’t a Fourth Amendment violation, multiplying a non-violation by a several million still doesn’t create a constitutional cause of action.

But now that the Supreme Court’s Carpenter decision is in play, things might change. That ruling said collecting long-term records of people’s movements via cell site location data required a warrant. This is pretty much the same thing, even if the network of ALPRs can’t necessarily produce the same amount of granular location data a person’s cell phone can.

The lawsuit [PDF] figures it’s a question worth asking, no matter what precedent exists. The network of ALPRs — run by contractor Vetted Security Systems and utilizing Vigilant’s software to maintain the collection of plate/location records — allows cops to track pretty much anyone traveling in or through Cook County, allowing them to determine where people worship, shop, seek medical help, or what political groups they associate with. So, there’s a First Amendment concern closely aligned with the more immediate Fourth Amendment-related cause for concern.

The lawsuit maintains that collecting plate data is a search under the Fourth Amendment and that the millions of “searches” performed by the plate readers cannot possibly be supported by probable cause or even reasonable suspicion.

It is an unreasonable search when the government tracks the movements of every citizen who drives a car just in case it might someday have reasonable suspicion as to one of the millions of people being tracked.

Defendants do not have any substantial or exigent government interest that would justify searching every citizen who drives a car, every day, and retaining that record of every citizen’s movements.

The plaintiffs seek an injunction blocking the State Police from utilizing its current ALPR system and preventing it from adding additional cameras to the network it already has in place.

It’s an interesting set of arguments. But it will be a tough case to win given the lower expectation of privacy given to drivers on public roads. Pretextual stops exist because of this lower constitutional standard and probable cause isn’t needed to engage in fishing expeditions. ALPRs have their problems but so far, no court has declared them unconstitutional to deploy without a warrant.

While there’s a slim chance a warrant requirement might someday surface in some court, it’s likely it will only affect searches of stored plate records, rather than deployment and use of the devices themselves. Unless this court is willing to buck the trend, the Illinois State Police is unlikely to lose access to its massive network of plate readers.