Surveillance and privacy issues have been in the news a lot in the past few years. Perhaps the biggest news was made by by Edward Snowden, who leaked information about the NSA’s massive collection of American citizens' cell phone data. But the privacy debate has also hit closer to home. You may remember last spring, when the Oakland City Council debated a controversial surveillance hub called the Domain Awareness Center, or DAC.

The hub was originally intended to protect the port against terrorist attacks, but city officials proposed expanding the scope to watch all of Oakland by pulling in security camera footage and sensors from around the city. Privacy activists protested, claiming the center’s purpose was less crime prevention and more spying on protesters, and the plan for an expanded DAC failed. But the controversy around the expanded DAC was just the beginning.

The Electronic Frontier Foundation (EFF), a non-profit that focuses on defending civil liberties in the digital world, looked into the controversial technology of automatic license plate readers (ALPRs). Little boxes are placed at intersections and affixed to police cars, and they constantly scan the streets for license plates. The devices can read up to 60 plates per second and they typically record the date, time, and GPS location of any plates. That is a lot of data being gathered everyday by these machines.

It also means, if you’ve driven through Oakland in the last few years, chances are the police know exactly where you’ve been. That fact rubbed the EFF’s Jeremy Gillula the wrong way.

“It’s the recording of everyone’s location and the retention of that data, that gets me, so to speak,” says Gillula.

Gillula and the EFF wanted to know how all that data was being used, so they did a study based on a week’s worth of these scans and mapped them out.

They found that there are ALPR hot spots -- places where there’s more tracking activity -- particularly in East and West Oakland.

The EFF says those hot spots seem to target certain groups of people. To get a better understanding of who is being tracked in these spaces, the EFF overlaid their maps of where license plates were being read with U.S. Census data, breaking down each area, nearly block by block, by ethnicity and income.

“You can see there was much more ALPR activity in areas of lower income and greater Hispanic and African-American populations,” Gillula says.

The Oakland Police Department says the main purpose of the program is to recover stolen vehicles, and that they focus on areas where auto theft is more common. The EFF fact-checked that claim using OPD’s own crime data. Gillula says they found there wasn’t a strong correlation between high numbers of auto thefts and ALPR hotspots.

Gillula says it also seems like the ALPRs are also recording parked cars -- which could mean the information stored is used for reasons beyond searching for stolen cars.

“It could constantly be picking up what cars are parked at an anarchist bookshop or what cars are parked at a church or a synagogue or a mosque or an adult novelty toy show,” he says. “Or a hospital. These are all things where you might not want the police to have this endless record of where you’ve been. But they do because they’re constantly scanning for these license plates.”

That’s what bothers privacy activists; the fact that this is a dragnet of surveillance, and that certain communities are watched more than others and all their data is stored in an easily searchable database.

Gillula says he’s concerned the OPD is compiling a database of residents' whereabouts without any clear indication of how that information will be used.

The Oakland Police Department says they really are using the latest technology to help bring back stolen cars.

Captain Anthony Toribio explains that when an officer gets an ALPR hit, he cross-checks the plates with the dispatcher to see if one of the license plates is on their hot list of wanted or stolen vehicles. Only .16% of the license plates they capture return stolen vehicles. Toribio says it’s still effective. Toribio also says that they aren’t keeping the information forever. He says after the license plate data is captured, the OPD keeps it for up to two years and then removes it from their system.

When asked about privacy concerns, Toribio answers that they are only tracking information that is already out in the open.

“The camera or that system is collecting information out in the public,” he says. “So it’s something that’s readily available and because it is in public. It’s something we’re collecting and utilizing for investigative purposes.”

But some who live in communities that are ALPR hot spots see it differently.

“When you introduce technology as a way to spy on people in communities of color, it becomes racial profiling on steroids,” says Cat Brooks, a privacy and social justice activist from Oakland. Brooks was one of those who protested the expansion of the Domain Awareness Center in 2014.

The increased reliance on technology to capture and store citizen data also worries Brian Hofer of the Oakland Privacy Working Group. He wants to make sure there is a way for the public to vet this type of technology before it is implemented. That’s why he’s working on a new privacy policy that will come before the Oakland city council on April 14th. Hofer says the most difficult part of all of this is distinguishing security equipment from surveillance.

“The definition of surveillance equipment will probably be the biggest dispute other than liability in the ordinance. Everyone I’ve spoken to the mayor’s office on down to Chief Whent of OPD supports retention limits of some amount,” Hofer says.

New technology is already being used in Oakland, technology like ShotSpotter, a gunshot detection tool that uses audio sensors to listen for gunshots. Privacy activists like Hoffer worry it could be abused as a city-wide microphone.

It’s a classic conundrum of private tracking in a public space. As this process unfolds, Hofer believes that Oakland is helping to set the standards for the growing privacy debate and that other cities are watching.

“Whether it’s a drone that requires warrants or the harvesting of cell phone location data, there’s a lot of privacy legislation being introduced,” says Hofer. “I have this wonderfully encouraging small voice in my head that says 2015 is going to be the year for privacy.”

As more monitoring technologies are introduced, Oakland will have to decide which ones are working to combat crime, and which ones cross the line into spying on citizens. Oakland, like so many places, will have to grapple with how private they want their public spaces.