Tracking Licence Plates - Another Invasion of Your Privacy

A report by the ACLU entitled "You Are Being Tracked" examines the use of license plate readers to track and record the movements of Americans.  This is a topic of particular interest given the revelations of Americans spying on Americans (and just about everyone else).

License plate readers are becoming ubiquitous in many nations including Canada and the United States.  They are essentially a high speed camera that is mounted on bridge overpasses, in police patrol cars and on posts along streets and highways.  These cameras capture an image of every passing license plate along with the vehicle, driver and front seat passenger and are promoted as being used to locate vehicles (and presumably their drivers) that are potentially guilty of a crime by checking the license plate numbers against a police "hot list".  They can also be used to track stolen vehicles and track people that have been registered as sex offenders or for such mundane legal issues as parking tickets.  The use of these systems is becoming increasingly widespread; in 2011, three-quarters of police agencies were using plate readers and it is estimated that within five years, plate readers will be installed on one-quarter of all police patrol cars.

Here is a video showing how effective these systems are at capturing your license plate numbers both at night and during the daytime:

For my Canadian readers, here is an example of a mobile system that Canadian police in British Columbia are using, even scanning all vehicles in shopping mall parking lots as they do a drive-through:

The problems with the system is:

1.) The licence plate numbers of all vehicles are recorded, not just those on the "hot list".

2.) The information is shared or pooled with similar systems in other jurisdictions, building a massive database of information.

3.) The data gathered can be retained permanently without restriction.

In case you wondered how this data could be accumulated and used, here is a map showing where Minneapolis police and traffic license plate readers found the city's Mayor's car between August 2011 and August 2012:

Minneapolis' eight mobile and two stationary cameras captured 4.9 million license plate images in 2012 alone and the city of St. Paul has an additional ten mobile cameras.  In the case of the city of Minneapolis, the scanned images are stored for 3 weeks.  Despite the potential for the invasion of privacy, here's what Minneapolis Mayor Rybak had to say about the issue:

"In some cases, the license plate data the police have retained have proven helpful in investigating and solving crimes....but there are important, legitimate concerns around the length of time it is stored and how it is or can be used or accessed that we need to address."


Let's look briefly at how much data is collected in three sample municipalities and how many hot list hits resulted:


Another example of the overkill involved in license plate data gathering is found in Minnesota as a whole.  Of the 1,691,031 plates scanned between 2009 and 2011, the Minnesota State Patrol issued only 852 citations and made only 131 arrests.  That is a measly 0.05 percent of all plates read.  Fortunately, Minnesota's policy is to delete all records within 48 hours unless there are "extenuating circumstances".  The same cannot be said for other jurisdictions as shown on this chart:

Who is funding all of these privacy-invading fun and games?  The federal government, that's who!  Through grants from the Department of Homeland Security and the Department of Justice, municipalities have received money that allow them to purchase license plate recording equipment.  Examples include New Castle County, Delaware; they received a DoJ grant of $200,000 which was used to purchase a system of eight license plate readers.  As well, the Maryland Transportation Authority Police used a $161,000 DoJ grant to purchase a system that included 14 license plate readers.


What is concerning about this issue is the gathering of hundreds of millions of location and time data points showing the travel histories of millions of motorists who have committed no crime.  This invasive tracking was covered in the United States v. Antoine Jones and Lawrence Maynard case which addressed the issue of a police GPS tracking system.  Here's what the court had to say about that issue:


"”The fact of the matter is that “[y]ou can preserve your anonymity from prying eyes, even in public, by traveling at night, through heavy traffic, in crowds, by using a circuitous route, disguising your appearance, passing in and out of buildings and being careful not to be followed. But there’s no hiding from the all-seeing network of GPS satellites that hover overhead, which never sleep, never blink, never get confused and never lose attention....Maynard recognized that the warrantless use of GPS “turn[s] a person into a broadcaster of his own affairs and travels, without his knowledge or consent, for as long as the government may wish to use him where no warrant places a limit on surveillance. To allow warrantless ...monitoring, particularly under the standard urged by the government here (‘reasonable suspicion’), would allow virtually limitless intrusion into the affairs of private citizens.”.   Nowhere does the government tackle this critical concern.’


While the use of police GPS tracking is one step further down the slippery slope of personal invasion, license plate readers allow law enforcement and anyone else with access to these systems (i.e. private contractors) to track virtually anyone including ex-husbands and ex-wives, girlfriends and boyfriends (and former of both), friends and enemies, neighbours, and co-workers and supervisors.


As in the case of capturing our personal cell phone, email and internet data, authorities can always justify the "slight" inconvenience of their intrusion into our privacy by touting the crime (and/or terrorism) fighting benefits.  Unfortunately, that means that we have to trust that our data will not be used for nefarious purposes.  Basically, we are putting our personal lives in the hands of the untrustworthy and that is frightening.


Let's close with a quote from Bruce Schneier:


"Once the technology is in place, there will always be the temptation to use it. And it is poor civic hygiene to install technologies that could someday facilitate a police state."