Tech Talk
Eye in the Sky / by Michael E. Duffy / October, 2016

PSS has made it possible to follow someone who commits a crime froward and backward(!) in time to see where they came from and where they go.

One venue for the application of technology, besides business (nominally what this column is supposed about), is the waging of war. I recently watched Eye in the Sky, starring Helen Mirren and the late Alan Rickman, and it paints a good picture of state-of-the-art drone warfare. I recommend it.

The Reaper UAV (Unmanned Aerial Vehicle) that’s used by the military (and depicted in the movie) has a wingspan of 66 feet and can stay airborne for 14 hours, fully loaded with munitions such as Hellfire missiles. Perhaps even more amazing are the tiny drones used to capture audio and video from inside houses. The Reaper, coupled with audio and video surveillance, is a powerful—and terrifying—expression of technology

One of the details that gets glossed over, however, is the satellites that are tracking the movements of people. With a wide-enough angle and the ability to record what the satellite sees, you can actually track people as they move between locations.

That very same capability is being employed by police in Baltimore, Md. A company named Persistent Surveillance Systems (PSS), funded by a private individual, flies a modified Cessna airplane over the city. Using an array of wide-angle, relatively low-resolution cameras, PSS has made it possible to follow someone who commits a crime forward and backward (!) in time to see where they came from and where they go. Bloomberg Businessweek published an in-depth story on the program in Baltimore ( on August 23, noting that the public (and even some police) were unaware of the program’s existence. The next day, the Baltimore Police Department acknowledged that the program has been in operation since January of this year.

As you might expect, the s**t proceeded to hit the fan, with the American Civil Liberties Union stating, “It continues to be stunning that American police forces feel that they can use deeply radical and controversial surveillance systems, without telling the public that will be subject to these technologies—the public they are supposed to be serving.”

Normal aerial surveillance is, as described by a Washington Post reporter, “like looking through a soda straw.” Regardless of the resolution, the view simply doesn’t cover a lot of area. The technological advance of the PSS system is that it uses multiple cameras, each with a soda-straw view, and stitches them together using software to provide a real-time image of about five square miles from a height of about 10,000 feet. From that altitude, people are single pixels, and cars only a few more, so you can’t identify faces or read license plates. But the large area of coverage allows, for example, to see where a perpetrator and victim came from, and where they went after a crime is committed. This five-minute YouTubve video from PSS demonstrates the system in action ( as it tracks activity surrounding a drug-related murder in Juarez, Mexico. The important thing is that it shows you how little detail is actually captured.

The BPD argues this technology is just an extension of its CitiWatch program of 700 street-view cameras, although that program is just voluntary registration of surveillance cameras owned and operated by private businesses. Citiwatch lets the police locate cameras that may have useful footage of a crime more quickly, but to say it’s the equivalent of PSS’s video time machine is, quite frankly, disingenuous.

Much of privacy law hinges on the Fourth Amendment to the United State Constitution, dealing with “[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.”

Of course, the Founding Fathers didn’t have a crystal ball to show them the future. Someone seeking protection under the Fourth Amendment needs to show that they had a “reasonable expectation of privacy.” Clearly, if you’re walking or driving around in public, it’s hard to argue for such an expectation.

Suppose however, that I visit my local Safeway and return home. At the same time, aerial surveillance shows that two people involved in a crime met at that location while I was shopping for Diet Coke and Pringles. Since the video doesn’t show any detail, do the police have a right to follow all the pixels (including me) home?

The general argument is, “If you have nothing to hide, you shouldn’t worry about it.” But to quote Edward Snowen, “Arguing that you don't care about the right to privacy because you have nothing to hide is no different than saying you don't care about free speech because you nothing to say.”

The issue, of course, is that this kind of surveillance power offers many possibilities for abuse. Suppose you like to have sex in your backyard. One would argue that you have a “reasonable expectation of privacy,” but, who knows? Maybe it’s best if you move indoors…at least if you live in Baltimore.