A Class-Action Lawsuit Against San Francisco Details How “Vehicle Fingerprints” Are Used in the Mass Surveillance of Drivers

​Michael Moore is a retired public-school teacher living in San Francisco. Nearly every day, as he drives to the store, to his sons’ schools, or to meet friends and family, his movements are watched and recorded at every turn. But he is not being tailed by a private detective or by the police.

Moore, like every other driver in San Francisco, is being tracked because he must navigate through the city’s network of almost 500 automated license plate readers (ALPRs).

These devices, operated by the San Francisco Police Department (SFPD), constitute a major link in the national surveillance network that the vendor Flock Safety is providing to state and local law enforcement. Moore has had enough. At the end of December, he filed a class action lawsuit in a federal courtroom on his behalf and on behalf of his fellow San Franciscans against the city and its police department over this continuous violation of their Fourth Amendment rights.

In his suit, Moore states that Flock ALPRs “make it functionally impossible to drive anywhere in the City without having one’s movement tracked, photographed, and stored in an AI-assisted database that enables the warrantless surveillance of one’s movements.”

Here are some of the topline revelations from Moore’s lawsuit:

Suspiciousness surveillance: Of the over 1 billion license plate scans collected by 82 agencies nationwide in 2019, “99.9 percent of this surveillance data was not actively related to any criminal investigation when it was collected.”

Creates “vehicle fingerprints”: “When Flock Cameras capture an image of a car, Flock’s software uses machine learning to create what Flock calls a ‘Vehicle Fingerprint.’ The ‘fingerprint’ includes the color and make and model of the car and any distinctive features, like an anti-Trump bumper sticker or roof rack. Flock’s software converts each of those details into text and stores them into an organized database.”

Tracks social networks: “Flock provides advanced search and artificial intelligence functions that SFPD officers can use to output a list of locations a car has been captured, create lists of cars that have visited specific locations, and even track cars that are seen together.”

Data stored indefinitely: “The data that Flock Cameras collect belong to the SFPD but Flock retains data on a rolling 30-day basis. Nothing, however, prevents the SFPD or its officers from downloading and saving the data for longer than SFPD’s 365-day retention period.”

Flock doesn’t just see and record – it thinks and analyzes:

“ALPR technology is a powerful surveillance tool that is used to invade the privacy of individuals and violate the rights of entire communities. ALPR systems collect and store location about drivers whose vehicles pass through ALPR cameras’ fields of view, which, along with the date and time of capture, can be organized by a database that develops a driver profile revealing sensitive details about where individuals work, live, associate, worship, protest and travel.”

Moore’s lawsuit poses a profound constitutional question: Can a city turn every resident into a perpetual suspect simply for driving on public roads?
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The Fourth Amendment was written to forbid dragnet surveillance untethered to suspicion, warrants, or individualized cause. Yet San Francisco has quietly constructed a system that records nearly every movement of its citizens, not because they are suspected of wrongdoing, but because technology makes it easy. If this practice is allowed to stand, the right to move freely without government monitoring may become a relic – honored in theory, but surrendered in practice to cameras, algorithms, and convenience.

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