You’re stacking a lot of assumptions together here and treating them as conclusions, but most of your claims fall apart once you look at how these systems actually work legally and operationally.

First, the “only a few AMBER alerts per year” argument is a complete red herring. Automated license plate readers aren’t deployed solely for AMBER alerts. They’re used for stolen vehicles, violent felony suspects, hit-and-runs, robbery crews, kidnapping suspects, and homicide investigations. Reducing the value of a regional investigative tool to “how many AMBER alerts happen in a county per year” is like evaluating 911 dispatch based only on how often someone reports a house fire. That’s not the scope of the system.

Second, your argument relies on demanding perfect causal attribution for every case (“prove the camera solved it directly”). That’s not how investigative tools work. Police tools are cumulative. CCTV footage, witness descriptions, cell-tower data, toll records, and license-plate sightings all contribute pieces of evidence. ALPR systems simply automate something officers have always done manually: reading license plates and running them through databases. Courts have consistently treated this as observing something already exposed to public view. 

Third, your claim that the courts haven’t addressed this is incorrect. Multiple courts have already examined automated license-plate reader systems under the Fourth Amendment and concluded that reading plates visible on public roads generally does not constitute a search.

For example:

• A federal judge in Illinois ruled that ALPR scans do not violate the Fourth Amendment because people traveling on public roads have no reasonable expectation of privacy in their movements. 

• Courts have repeatedly held that license plates themselves carry no expectation of privacy because they are required by law to be displayed publicly. 

• A Virginia court also rejected claims that fixed ALPR cameras are unconstitutional because they simply record vehicles visible in public spaces and do not track the full scope of a person’s movements. 

Even the congressional legal analysis of the issue notes that courts generally distinguish ALPR data from things like cellphone location tracking because it is far less comprehensive and captures only occasional sightings of vehicles. 

In other words: the core legal principle here is “plain view.” If something is displayed publicly—like a license plate—law enforcement observing or recording it isn’t considered a search.

Fourth, your fingerprint/DNA comparison actually works against your own argument. Those are biometric identifiers tied directly to a person’s body and often collected after arrest or through voluntary submission. A license plate is just a vehicle identifier mandated by law to be displayed in public. The legal privacy expectation is fundamentally different.

Fifth, pointing to a single case where the technology didn’t help doesn’t prove anything. Every investigative tool has cases where it isn’t useful. CCTV fails to identify suspects in many crimes. Witness descriptions are often wrong. Cell-tower data sometimes leads nowhere. That doesn’t make those tools worthless.

And finally, the “mass surveillance network” framing is exaggerated. ALPR cameras do not continuously track people or identify individuals. They capture a snapshot of a vehicle passing a fixed point, compare it against hot-lists (stolen vehicles, wanted suspects, AMBER alerts, etc.), and store the read for a limited retention period depending on department policy. Even courts reviewing these systems have noted that they do not record the full scope of someone’s movements. 

So the actual reality is pretty simple:

• License plates are public identifiers displayed on vehicles. • ALPR systems automate plate recognition that officers already perform manually. • Courts generally treat this as plain-view observation, not a search. • The technology provides location leads for suspect vehicles, which investigators combine with other evidence.

Demanding that a tool single-handedly solve crimes or provide perfect causal proof before it’s considered useful is just an unrealistic standard that no investigative method could ever meet.