The records and other publicly available information confirm that over 80 Massachusetts police departments have entered into contracts to deploy Flock Safety’s automatic license plate reader (LPR) technology to surveil drivers when they pass one of Flock’s cameras on the roads. Over the past three years, Massachusetts police have spent over $2 million in taxpayer funds on this technology. Many of these departments have been sharing LPR data collected in their jurisdiction with Flock to be entered into its national database, where it can be accessed by thousands of out-of-state police departments and even federal agencies.  

At minimum, this dragnet surveillance means warrantless tracking of everyone on the road. At worst, it means a digital police state wherein law enforcement officials in far-flung jurisdictions outside of Massachusetts can track protesters, political opponents, immigrants, patients, and others not suspected of any crime and use the information to hurt them. 

What Is Flock and How Does It Work? 

Flock Safety is a major player in the LPR industry, contracting with thousands of law enforcement agencies, running LPR surveillance across nearly 7,000 networks, and deploying nearly 90,000 cameras nationwide as of July 2025. The company’s CEO claims their technology can eradicate all crime in America — though that’s more marketing hype than reality. 

License plate readers are cameras that automatically capture and record license plates, locations, and timestamps as vehicles pass by. These AI-enabled systems allow police to instantly track where motorists are now and where they’ve been. 

At the crux of the problems with Flock is their nationwide data sharing model. Police departments that contract with Flock can choose to share the LPR data they collect with no other departments, with specific named departments, with all departments in their state, or with the entire Flock network nationwide. But Flock has designed its system to incentivize maximum sharing: if a police department chooses to share their data with the entire nationwide network, that department can also search the entire nationwide network. In effect: “You show me yours, I’ll show you mine.” This Flock training video received in response to public records requests demonstrates how seamless and unrestricted data sharing operates within Flock’s system. To share their data with police nationwide, all an administrator needs to do is click a button: 

We know many Massachusetts police departments are taking part in this nationwide network because, after submitting public records requests with nearly 80 departments, we received numerous records called “Flock Network Audits[.]” These network audits document searches conducted by police across the country of approximately 7,000 agencies and organizations’ LPR data, including data on Massachusetts drivers collected by dozens of Massachusetts police departments. What this means in practice is that officers with the Florida Highway Patrol and those in Dallas, TX, Jacksonville, FL, Columbus, OH, and thousands of other locations can track where and when Massachusetts residents are driving, even when they are in Massachusetts — all without demonstrating any probable cause or even reasonable suspicion that those people have committed a crime.  

Even some federal law enforcement agencies may have access to Flock’s database, despite Flock’s recent assertion that it ended its pilot program with the Department of Homeland Security’s Customs and Border Protection (CBP). News reports indicate local police have conducted searches on behalf of ICE agents.  

And that’s not all. Flock isn’t the only license plate reader company with a large presence in Massachusetts. The Massachusetts State Police (MSP) and some local departments also have contracts with Vigilant Solutions, a company that maintains its own national database and has contracts with agencies nationwide — including those in states that have passed extreme restrictions on abortion and gender affirming healthcare access. Vigilant also has contracts with federal agencies, including ICE. Indeed, records obtained through a public records request to the town of Auburn, Massachusetts show ICE agents have direct access to query the Vigilant database. The ACLU of Massachusetts is currently involved in public records litigation to learn more about the MSP’s license plate reader surveillance network and its statewide LPR tracking database. Stay tuned for more details as that litigation progresses. 

Is Warrantless, Dragnet Surveillance of Motorists Legal? 

In 2014, in Commonwealth v. Augustine, the Massachusetts Supreme Judicial Court held that police are required to obtain a search warrant to access cell site location information under the Massachusetts Constitution, the Declaration of Rights. Four years later, the Supreme Court applied similar protections nationwide in Carpenter v. United States. The Court reasoned that technology enabling the government to track everyone, to monitor all our public movements, and to do so both in real time and retroactively, posed a significant threat to our Fourth Amendment rights.  

LPRs are analogous to cellphone tracking. These AI-enabled cameras track motorists in real-time and historically, giving the government the means to track people’s locations in a manner similar to the cell site location information at issue in Augustine and Carpenter. 

The Massachusetts Supreme Judicial Court recognized this in 2020, holding in Commonwealth v. McCarthy that “[w]ith enough cameras in enough locations, the historic location data from an [LPR] system in Massachusetts would invade a reasonable expectation of privacy and would constitute a search for constitutional purposes.” Yet today, police in Massachusetts are subject to no state or federal statute governing their use of automatic license plate readers. In the absence of a state statute, police are engaged in mass surveillance of all drivers. 

Flock’s Data Sharing Model vs. the Massachusetts Shield Law 

In August 2024, Massachusetts strengthened its Shield Law, which prohibits Massachusetts law enforcement from providing information or assistance to any other state’s law enforcement agency in relation to investigations into reproductive healthcare or gender-affirming healthcare that is lawful in the Commonwealth. The Shield Law was designed to protect people from other states’ laws that criminalize abortion and restrict access to gender-affirming care, ensuring that people who receive and provide protected healthcare that is lawful in Massachusetts can do so without fear of retribution from out-of-state actors.  

But Massachusetts law enforcement’s use of Flock’s nationwide data sharing undermines the effectiveness of the Shield Law. Out-of-state officers from thousands of agencies across the country can and do access information about where and when people are driving in Massachusetts, and there is nothing stopping them from using that information to track the movements of people in Massachusetts who are seeking or providing protected healthcare. 

These concerns are not hypothetical. Earlier this year, police in Johnson County, Texas performed a nationwide search in Flock’s database to find a woman who they believed had a self-administered abortion — searching LPR data from many states where abortion is legal and protected, including Massachusetts. We know about this investigation because the Texas officer entered “had an abortion, search for female” in the “Reason” field in Flock’s database. Initially, Flock tried to dismiss criticism stemming from the negative press, suggesting that the woman’s “family feared she was hurt” and that police merely sought to make sure that she was alright. But subsequent reporting from 404 Media based on public records obtained by the Electronic Frontier Foundation show the police who made this search were pursuing the woman as part of a “death investigation” into the abortion. As 404 Media reporters put it: “In documents created prior to the publication of our article, there is zero mention of concern about the woman’s safety. The records show that the police retroactively created a separate document about the Flock search a week after our article was published, in which they justify the search by saying they were concerned for her safety.” 

Flock claims it protects people’s privacy and legal rights by requiring all law enforcement officers to enter a “search reason” before accessing database results. According to Flock’s recent response to similar data sharing concerns in other states, if an out-of-state officer enters a reason that would violate a state law that protects access to reproductive and gender-affirming healthcare (for example, Massachusetts’ Shield Law), that state’s LPR data would be excluded from the search results. But the Flock network audits obtained by the ACLU of Massachusetts demonstrate that the company’s measures are woefully inadequate. 

The network audits show police frequently enter vague, tautological terms like “investigation” or “susp” instead of information about the substance of the investigation. But even if Flock were to prohibit officers from accessing search data unless they provide a substantive reason, police could evade the system’s guardrails. As Flock’s technology attracts more negative media attention and scrutiny from public officials concerned about its data sharing practices, officers in states that criminalize abortion and gender-affirming healthcare could simply decline to provide specific details about their investigations or use terms like “homicide” or “suspicious death” when investigating an abortion case. The scale of the nationwide searches makes case-by-case oversight impossible. For example, a Flock network audit provided to the ACLU of Massachusetts in response to a July 2025 public records request documents over 450,000 searches of the nationwide database in just a 30-day period in the spring of 2025. 

Flock’s purported solution to comply with state laws that restrict the sharing of information related to investigations of protected healthcare services is no solution at all. Today, out-of-state officers continue to have effectively unrestricted access to Flock’s nationwide database, including data about Massachusetts residents and visitors. 

Flock’s Contract Problem 

Police departments that use Flock and seek to protect the rights of Massachusetts residents from out-of-state or federal scrutiny must turn off information sharing settings authorizing those entities from searching the data they collect. But even when departments opt to restrict sharing in Flock’s system settings, they may not actually be protecting people’s privacy. According to public records reviewed by the ACLU of Massachusetts, the template user agreement many law enforcement agencies sign gives Flock “a non-exclusive, worldwide, perpetual, royalty-free right and license (during and after the Service Term hereof) to (i) use and distribute [] Aggregated Data to improve and enhance the Services and for other development, diagnostic and corrective purposes, other Flock offerings, and crime prevention efforts, and (ii) disclose the Agency Data (both inclusive of any Footage) to enable law enforcement monitoring against law enforcement hotlists as well as provide Footage search access to law enforcement for investigative purposes only” [italics added for emphasis].

What this means in practice is troubling: even when a police department chooses in Flock’s application to restrict data access to its own officers, the template agreement gives Flock the right to disclose the local police department’s data both to law enforcement nationwide and federal agencies for “investigative purposes.” 

Individual police departments can, and sometimes have, addressed this problem by amending Flock’s contract language. For example, when the Boston Police Department (BPD) conducted a pilot of Flock’s technology earlier this year, the department elected in its sharing settings not to share data outside the department — but the BPD also appears to have rewritten Flock’s template contract. Unlike the template contract language that many police departments have agreed to, the Boston Police Department’s agreement does not give Flock the right to disclose its LPR data. 

But the vast majority of police departments in Massachusetts lack the legal resources and sophistication of Boston’s department, putting them at a serious disadvantage. Flock, which recently received a large investment from Andreessen Horowitz, has been engaged in an aggressive marketing campaign to win more contracts and secure more taxpayer dollars. This campaign includes potent sales tactics, such as invitations to participate in a free TopGolf event and an opportunity for agencies to participate in Flock’s “Project Prove It[,]” in which Flock installs LPR cameras on the roads and the agency can back out at no cost within 45 days. Flock sales staff also offer to work with local Massachusetts departments and other municipal leaders to identify and apply for grant funding for Flock LPR systems. 

Faced with this onslaught from a company with seemingly endless resources at its disposal, small- and medium-sized police departments across the country are falling prey to aggressive marketing and sales pitches. Individual action by sophisticated departments like Boston’s isn’t enough. Residents in communities with less well-resourced departments deserve protection too.  

How Lawmakers and Law Enforcement Can Address Issues with LPRs 

The scope and severity of this dragnet surveillance make clear that both legislative action and individual police department changes are needed to achieve statewide protections from unrestricted LPR use. 

First, state lawmakers must pass comprehensive LPR legislation. H.3755 strikes the right balance, protecting civil rights and civil liberties while allowing police to use LPRs for legitimate investigations. The bill prohibits law enforcement from using LPRs to monitor individuals based on First Amendment-protected activities, including political protests or religious gatherings. It requires that LPR data be deleted within 14 days unless a record is tied to a specific, ongoing criminal investigation supported by articulable facts. Access to LPR data would be limited to law enforcement for investigative purposes and could not be disclosed outside judicial proceedings. The bill also prohibits buying, selling, renting, or sharing LPR and related location data unless required by judicial process, and bars law enforcement from accessing LPR data collected by another entity without a valid search warrant. These provisions prevent the accumulation and sharing of data on millions of people not suspected of any wrongdoing, while allowing law enforcement to use LPRs in legitimate criminal investigations. This legislation would ensure consistent protections apply for all Massachusetts residents. 

Second, police departments must take immediate action. Individual departments should stop voluntarily sharing data with out-of-state and federal agencies. They should redraft contracts with Flock to ensure their department retains full control of all data they collect. Finally, police departments must adopt internal policies requiring that every Flock network search be justified by a specific, documented reason for the inquiry, clarifying to all officers and staff that a non-descriptive entry like “investigation” will not suffice. 

Take Action 

Right now, your movements on Massachusetts roads are being tracked and shared with thousands of agencies nationwide. No warrant, no suspicion, no safeguards. 

Join us in calling on the Massachusetts Legislature to pass common sense checks and balances on police use of license plate readers, to ensure that you retain basic civil liberties on the road.  

Email your state legislators today to show your support for H.3755, An Act Establishing Driver Privacy Protections.

This post was updated on February 26, 2026, to reflect that more than 80 police departments across Massachusetts have contracts with Flock Safety.

Review Boston Police SWAT After-Action Reports

About the data 

This analysis draws on after-action reports of BPD SWAT incidents from 2012 to May 2020. After-action reports are created by the BPD SWAT team to document the unit’s deployments. The reports include descriptions of the incident, information about the people involved (the police, targets, and others impacted), the geographic location of the deployment, and details about the level of police force used during the SWAT action, among other details. The BPD released these reports in response to a 2020 subpoena from then-City Councilor Michelle Wu.  

Unfortunately, the documents produced by the BPD were difficult to analyze in bulk; among other problems, they were not machine readable. While the ACLU and our partners made every attempt to ensure the accuracy of the data pulled from these reports, our analysis has some data limitations. For example, the underlying after-action reports occasionally include missing, clearly incorrect, or difficult-to-interpret data. As explained in greater detail in the methodology section at the bottom, some errors may also have arisen in our processing of the records and extraction of information. That said, we engaged in a human review of the documents to ensure any errors in our extraction do not impact the overall analysis of trends.  

The data: Disproportionate SWAT policing of Black and Brown communities and people

There are 262 after-action incident reports representing deployments between 2012 and May 2020. A significant portion of these police actions took place in police precincts roughly corresponding to the neighborhoods of Mattapan, Roxbury, and Dorchester.  

According to data reported by the Boston Planning & Development Agency Research Division, these three neighborhoods had the highest percentage of residents who are non-white (i.e., identifying as a race other than white or as white along with one more other races) of any Boston neighborhood in 2020. These neighborhoods also had a relatively higher share of residents identifying as Black or African American and/or Hispanic than most other Boston neighborhoods.   

After-action reports typically list one or more “incident types” indicating the reason(s) for the raid. In order of frequency, the most common types were Search Warrant – Other/Unknown, Search Warrant – Drugs, Mental Health Crisis, and Barricaded Suspect. 

Like other SWAT teams, the BPD SWAT unit is deployed in response to active crises and in deliberate, planned SWAT raids. Typically, the latter cases involve the serving of search and arrest warrants. While the BPD has discretion about whether to deploy the SWAT unit in response to calls for service, SWAT deployments pertaining to active emergencies like mental health crises, barricaded suspects, and domestic violence incidents are nonetheless responsive to active emergencies in the community. On the other hand, the deployment of the SWAT unit to serve warrants, particularly search warrants, is more reflective of self-directed police work. For that reason, racial disparities in the use of SWAT units to serve search warrants are a significant cause for concern.  

Data indicate that white and Black people in the United States use and sell drugs at approximately the same rates. But the BPD’s SWAT unit serves drug warrants almost exclusively on people of color.  

The data: Targets of the BPD’s SWAT raids

According to the after-action reports, 784 people were subjected to SWAT raids between 2012 and 2020. 270 of these individuals were specifically marked as the “suspects” or “targets” of the raid.  

The ages of all raid subjects ranged widely from infants to 83-year-olds. Individuals between 20 and 40 years old were the largest group impacted. For those marked specifically as raid suspects or targets there is a smaller range of ages; the youngest person was 16 and the oldest was 67.  

According to the reports, 105 children under the age of 18, including 25 children under the age of 5, lived in homes subjected to BPD SWAT raids between 2012 and early-2020. 

Those impacted by raids were predominantly men, accounting for 88% of those targeted by raids and 62% of all individuals subjected to raids. When considering both race and gender, Black men were the largest group of those both subjected to raids (38%) and marked as raid suspects/targets (50%).

There are significant racial disparities in those targeted and all those impacted by raids — 56.3% of those targeted by raids were Black non-Hispanic and 8.5% were Black Hispanic. These figures are disproportionate to the share of Black residents in Boston. As of the 2020 Census, 25.5% of Boston’s population was Black or African American; this figure includes multiracial residents and both Hispanic and non-Hispanic residents. Of this, 22% of Boston’s population was Black non-Hispanic, and 3.4% was Black Hispanic. Hispanic residents are also disproportionately impacted by raids. 28.7% of those targeted by raids were recorded as Hispanic, White Hispanic, or Black Hispanic; however, the 2020 Census found that Hispanic or Latino residents made just 19% of Boston’s population. 

The disproportionate share of Black and Hispanic individuals impacted by raids varies by incident type; the disparity is notable in “officer-initiated” raids* such as those for search warrants. In contrast, the demographics of people subjected to SWAT team involvement in crisis-related incidents, such as mental health crises, more closely reflect the demographics of Boston.  

*To better understand BPD SWAT unit practices, we categorized incident types into “officer-initiated” incidents such as search warrants or arrest warrants and “crisis-related” incident types that reflect an emergency such as a mental health crisis. 

Another way to view this disparity is to look at the share of white non-Hispanic residents impacted by raids. White non-Hispanic people are underrepresented in officer-initiated raids; Boston’s population is 44.6% white non-Hispanic, but the group of people impacted by all officer-initiated raids are only 6.5% white. In contrast, white people were involved in crisis-related raids at a rate more proportionate to the overall population; 33.5% of those impacted by these raids are white.  

The data: SWAT team after-action reports document frightening, militarized surprise raids 

Reports detail the SWAT team battering down doors, deploying aerosol grenades, waking individuals asleep in bed, and detaining relatives of suspects and children. According to the reports, well over half of the people subjected to this level of force were not even the targets of the operation but were just roommates, partners, family members, or children who were present in the home during the raid.  

SWAT raids can even harm people who live nearby a person wanted by police. One of the records details a raid where the entire household was not the target of the operation; the SWAT team failed to go to the correct address on a search warrant and wrongfully invaded another family’s home. In 2018, the ACLU of Massachusetts represented this family in a lawsuit against the BPD. As our lawsuit on behalf of the family alleged, “[the BPD SWAT team] used a battering ram to break down the door, trained guns on and handcuffed the parents … and their 15-year-old child, and ransacked the home with two younger children present.” The family suffered lasting emotional distress from this assault. Ultimately, the case was settled and the City was forced to pay the family $500,000.  

If you are interested in learning more about the practices of the BPD SWAT team, please use the interactive BPD SWAT records review tool. In addition to exploring the data, you can also read the original after-action reports, which include a narrative description of the incident at the end of each document. Please don’t hesitate to contact [email protected] with any significant findings.

Review Boston Police SWAT After-Action Reports

Data Notes and Methodology

The original incident reports were made public as non-machine-readable PDFs. Therefore, the first task of this project involved determining how to extract information from these files in a usable format. Volunteer data scientists began by OCR-ing and processing the PDF files to extract useful fields from the documents. Due to the nature of the PDFs and occasional image quality issues, the programmatic data processing and extraction of these reports was subject to error. As a final measure to address any errors and ensure overall data quality, selected fields were manually reviewed and updated by volunteers. For additional data documentation please see the “data notes” section of the BPD SWAT tool.  

This data extraction project was possible with the support of: 

• Tarak Shah, Human Rights Data Analysis Group — programmatically extracted data from the after-action report PDFs 
• Aaron Boxer, ACLU-MA volunteer — conducted data extraction, processing, manual entry, and analysis 
• Natasha Ceol, ACLU-MA volunteer — assisted with data quality-checking and redaction of the after-action reports.  

On April 12, Mayor Wu submitted her recommended operating budget for the upcoming fiscal year (FY24) to the Boston City Council, kicking off the public portion of the City’s budgeting process. Among other investments, the Mayor’s budget proposes funding the police department at $9.88 million over its FY23 budget. 

Over the coming months, the City Council will review the Mayor’s budget recommendation and can propose and vote on changes. During this same review period last year for the FY23 budget, the City Council unanimously proposed reducing funding for the police department and increasing funding for youth engagement and employment programming, among other proposed changes. These efforts had a limited impact in 2023, however. The Mayor’s budget passed with a few small tweaks from the Council.  

This analysis focuses on the Boston Police Department’s (BPD) budget. Our hope is that this breakdown will be useful for community members, journalists, and other interested parties as the City’s various stakeholders and residents engage in conversations and debate on the budget, which are set to take place between now and July. To explore the full recommended operating budget and design your own changes, please see our (Co)Design the Boston Budget calculator tool.

The analysis benefitted from feedback and input from Fatema Ahmad (MJL), Lauren Chambers (UC Berkeley I School; ACLUM), and Youth Justice and Power Union. Data analysis was informed by work done in collaboration with Boston University students under the supervision of the BU Spark! Program.