Privacy. It’s on everyone’s minds these days. A couple of months ago it was Apple and Google that were drawing the ire of consumers with the storing of location data. And of course, Facebook is always mentioned when people discuss their concerns about online privacy. But as technology gets better, and the tools used to capture information and the databases used to store and disseminate the information become more capable, the lines between online and offline privacy continue to blur.

On that note, let’s say that you are having a Sunday afternoon picnic with your child. The weather’s good, you’ve been running around and playing – but now it’s time for lunch. You open up the cooler, only to discover that you’ve left a couple of the sandwiches in the car. The car’s just a few yards away, so you quickly run to grab the sandwiches.

And in a split second, you look back to see that your child is gone. You catch a black sedan speeding away and you are barely able to catch the license plate. Because you caught that license plate, police are able to search a giant database of plate captures and track the movements of the kidnapper.

A classic question: What is more important, public safety or personal freedom? What are you willing to sacrifice? Let us know in the comments.

Ok, I know this whole scenario seems a little bit Without A Trace or Lifetime movie-esque, but the point is that police were able to use an ever-expanding database of data culled from license plate snapshots in order to generate real-time location information. That’s a reality, and it’s happening in our nation’s capital, among other places.

The Washington Post is reporting that police in D.C. are beefing up the area covered by license plate cameras. More than 250 cameras in D.C. and its suburbs are constantly hard at work, grabbing license plate numbers and sticking them into databases. The police aren’t exactly doing this quietly, but it’s being done with “virtually no public debate.”

The highest concentration of these plate readers in the entire nation exists in D.C. (one reader per square mile), so that means that District police are building the biggest location database based on license plates in the whole country.

Let’s take a brief look at these license plate readers.

First, these are apparently different types of cameras than the cameras cities have been affixing near stoplights and other places to catch people running red lights or speeding – the “here’s a ticket 2 weeks later in the mail” cameras.

These plate readers cost about $20,000 each and can snatch images of numbers and letters on cars traveling nearly 150 mph and across four lanes of traffic. These plate readers in D.C. take 1,800 images per minute, every one of which is stored in a database.

Basically, these plate readers have made it possible for police to track everyone’s movements as they move across the city.

These plate readers and the subsequent database of image captures has tipped the privacy concerns of some – notably the American Civil Liberties Union. One of their main concerns is naturally the privacy implications.

In the District, laws are in place that limit the amount of time that surveillance camera footage can be kept. The images must be dumped after 10 days, unless there is an actual investigatory reason to keep them. But right now, there is nothing keeping data from the plate readers from being stored for years.

The ACLU says that this database is storing the location data of innocent people. And they are right. The plate readers are casting an all-inclusive net, grabbing license plate numbers indiscriminately.

Clearly this technology is rapidly approaching the point where it could be used to reconstruct the entire movements of any individual vehicle. As we have argued in the context of GPS tracking that level of intrusion on private life is something that the police should not be able to engage in without a warrant.

Let’s think back to the slightly-stylized child abduction scene from the beginning of this article. Maybe that seems a bit far-fetched, but the reality of the situation is that the plate reader database has helped police. According to the D.C. police department, they make an arrest a day with the help of the plate readers. In a four month period this year, they also found 51 stolen cars.

And although our child abduction story above might seem unrealistic, the possibilities are there for the plate readers to help in truly significant ways. Police could track cars to and from murder scenes or use it to identify players in organized crime circles like sex trafficking – by logging which cars travel between certain locations.

But the fact that the technology is beneficial or could be beneficial in terms of law enforcement does not assuage concerns of a “surveillance society” becoming the norm in the U.S. It’s a classic argument that pits personal liberties against security and safety. Just how much of your freedom are you able to give up to feel safer? This is a crucial debate that we’ve seen play out most recently after 9/11 with the Patriot Act.

The ACLU channels Minority Report to discuss preemptive law enforcement:

Of course, if the police track all of us all the time, there is no doubt that will help to solve some crimes — just as it would no doubt help solve some crimes if they could read everybody’s e-mail and install cameras in everybody’s homes. But in a free society, we don’t let the police watch over us just because we might do something wrong. That is not the balance struck by our Constitution and is not the balance we should strike in our policymaking.

Obviously, the plate readers are a valuable tool for the police, and there are an abundance of situations where one could imagine the searchable database of plate captures to be extremely useful. But are those plate readers building up a database that’s just a little too full of innocent people’s location information for your liking?

If this kind of thing is to proliferate (both in D.C. and across the country), it is argued that it needs to see the light of day. Basically, society should have time to debate its merits and discuss their concerns. “The police should not be able to run out and buy a new technology and put it in place before anybody realizes what’s going on,” says Jay Stanley of the ACLU’s Privacy and Technology Program.

What do you think about the expansion of the plate reader technology? Do the benefits outweigh the privacy and personal freedom concerns? Or is this an example of big brother yielding too much power with the ability to catalog this data without warrants? Let us know in the comments.