License Plate Cameras Are Now Tracking Far More Than Just Your Car
If you assumed that a license plate camera could only capture your car's registration number, it's time to think again. A new generation of automatic license plate readers (ALPRs) is already deployed across the United States, and the technology embedded inside them has quietly evolved into something far more invasive. These devices are now capable of scraping electronic hardware codes from the smartphones in your pocket, the smartwatch on your wrist, your child's AirTag, and even your pet's microchip — all without a warrant, all without your knowledge, and critically, without any meaningful legal framework to stop it.
This isn't a hypothetical future threat. It is happening right now, and the implications for everyday Americans are profound.
What Is SignalTrace and How Does It Work?
The technology driving this expanded surveillance capability is called SignalTrace. Surveillance companies have integrated SignalTrace sensors directly into standard ALPR hardware, dramatically expanding what these roadside devices can collect. While an ALPR has traditionally photographed license plates and cross-referenced them against databases, SignalTrace allows the same device to passively detect and log the unique hardware identifiers broadcast by nearby electronic devices.
Any device that emits a Bluetooth, Wi-Fi, or similar wireless signal can be fingerprinted by this technology. That means the list of things being tracked extends well beyond your vehicle to include:
- Smartphones and tablets in your car or on your person
- Smartwatches and smart rings
- Vehicle infotainment systems and connected car modules
- AirTags placed in children's backpacks for safety purposes
- Pet microchips that emit detectable signals
Each of these devices carries a unique hardware identifier. When correlated across multiple ALPR camera locations over time, these identifiers can paint an extraordinarily detailed picture of your daily movements, routines, relationships, and behaviors — all without law enforcement ever needing to apply for a warrant.
It's Already Being Marketed to Law Enforcement
What makes SignalTrace particularly alarming isn't just its technical capability — it's how quickly and openly it is being commercialized and sold to government agencies. Surveillance companies are actively marketing this expanded ALPR technology to police departments, border security agencies, and other law enforcement bodies across the country.
The pitch is straightforward: give officers a richer, more interconnected dataset that links a vehicle to all of the devices traveling with it. In theory, this could help identify suspects or track persons of interest. In practice, the absence of any legal guardrails means the same tools are wide open for misuse — and that misuse has already begun. Reports have already surfaced of police officers using standard license plate readers to stalk individuals, raising urgent red flags about what happens when even more powerful tracking capabilities are placed in the hands of departments with little to no oversight.
There Is No Opt-Out and No Legal Protection
Perhaps the most unsettling aspect of this situation is the complete lack of recourse available to ordinary citizens. There is currently no mechanism to opt out of ALPR scanning or SignalTrace data collection. You cannot ask to have your device identifiers removed from these databases. You cannot consent — or refuse to consent — because the collection happens passively as you drive past a camera mounted on a highway overpass, a police cruiser, or a streetlight.
The law has simply not kept pace with the technology. Security expert Matt Hurewitz, currently serving as CISO at Ent.AI, addressed this gap plainly in a recent episode of The Drivecast: "The laws are way behind." He went further, warning that meaningful legislative change is unlikely to arrive until the technology inflicts visible, documented harm on real people — at which point, of course, the damage will already have been done.
This is not a new problem unique to ALPRs. It reflects a broader and deeply troubling pattern in American surveillance law: technology races ahead, agencies adopt it with enthusiasm, and Congress responds only after years of documented abuse have accumulated. By that measure, the clock on ALPR-based mass tracking has already been running for some time.
Why Connected Vehicles Make This Even Worse
Even if you were to leave your smartphone at home and strip every wearable from your body, your modern vehicle would still betray your location and identity. Today's connected cars are rolling data centers, continuously broadcasting signals from onboard modules, infotainment systems, and telematics units. Security researchers have demonstrated just how difficult it is to meaningfully disconnect a modern vehicle from its various data streams. For the vast majority of drivers, it is effectively impossible without specialized technical knowledge.
This means that for most people, simply getting in their car and driving to work, a medical appointment, a place of worship, or a political rally creates a permanent, timestamped record — one that can be accessed by law enforcement or private companies without judicial oversight.
The Broader Privacy Crisis This Represents
License plate camera surveillance is just one visible thread in a much larger tapestry of warrantless data collection. The United States currently lacks a comprehensive federal privacy law governing how surveillance companies can collect, store, sell, or share the data gathered by ALPRs and similar technologies. Individual states have begun to push back — a small number have introduced legislation to regulate ALPR data retention — but patchwork state laws do little to protect citizens crossing state lines or moving through federally managed spaces.
Civil liberties organizations have warned for years that the combination of ubiquitous cameras, powerful analytics, and weak legal protections creates the conditions for a surveillance infrastructure that would have been unthinkable just two decades ago. SignalTrace is not the beginning of that story. It is, however, a significant escalation.
What You Can Do Right Now
While a complete technical solution is out of reach for most people, there are steps that privacy-conscious individuals can take to reduce their exposure. Disabling Bluetooth and Wi-Fi on devices when not in use limits the signals available for passive collection. Using a VPN and being selective about which apps have location permissions adds additional layers. Staying informed and supporting organizations that advocate for stronger digital privacy legislation is arguably the most impactful long-term action any individual can take.
Pandora's box, as one observer put it, is now open. The question is whether lawmakers, courts, and citizens will demand accountability before this technology becomes so embedded in law enforcement practice that rolling it back becomes politically and practically impossible. Based on history, the window for that conversation is narrowing fast.