American Civil Liberties Union

Eye tracking technology received new attention recently due to its inclusion in the Samsung Galaxy IV phone, where it can (with mixed results, according to reviewers) let users scroll the screen with their eyes or dim the screen when they look away. Clearly this is a technology that has the potential for a lot of clever applications. But what are the privacy implications?

Eye tracking for research was used for over a century before computers (see the quick history outlined in this article). The earliest research, in the 19^th century, actually involved direct mechanical contact with the cornea. Already by 1898, researchers were discovering some really cool phenomena of the human brain. Motion pictures were applied to the problem as early as 1905, and the first head-mounted eye-tracker was developed in 1948, which freed study subjects from having to keep their heads still. In the mid-1970s the first remote trackers were developed that were truly unobtrusive to the subject. By then, research and writing based on eye tracking was booming, not only on the part of psychologists but also the military.

We’ve been doing a fair amount of thinking about the implications of consumer wearable cameras like Google Glass, and I’m sure we’ll have more to say in this space on the subject. But meanwhile, we’re pleasantly surprised to report a very trenchant analysis of the technology’s implications for our privacy by none other than Michael Chertoff. Writing on CNN’s web page, the former DHS chief writes,

So, who owns and what happens to the user's [video] data? Can the entire database be mined and analyzed for commercial purposes? What rules will apply when law enforcement seeks access to the data for a criminal or national security investigation? For how long will the data be retained? ….

Even those who might be willing to forgo some degree of privacy to enhance national security should be concerned about a corporate America that will have an unrestricted continuous video record of millions.

What is to prevent a corporation from targeting a particular individual, using face recognition technology to assemble all uploaded videos in which he appears, and effectively constructing a surveillance record that can be used to analyze his life?

Chertoff says he’s inclined to think that government regulation may be needed. I haven’t seen Chertoff say anything about the threat of pervasive government surveillance, which would make him a kind of anti-libertarian on privacy—in favor of restricting corporations, but not the government. For the average, relatively powerless person trying to live their life, the threat comes from both directions.

It's no secret that, after 9/11, a wave of anti-Muslim bigotry washed over the country. The intensity of that prejudice has sustained it for a decade, and, in many ways, anti-Muslim sentiment and fear of Islam seem even stronger and more deeply rooted today than in the months and years after the attack. In the last few years, for instance, a number Muslims or people perceived to be Muslims have been violently assaulted; and scores of mosques and Islamic Centers have been vandalized, with attacks ranging from racist and anti-Muslim graffiti to arson and firebombing.

Former Senator Joseph Lieberman recently charged that mistakes by U.S. security agencies were responsible for failing to stop the Boston Marathon bombing. I recently wrote about how mass surveillance makes this kind of recrimination inevitable, because once a government agency spies on a person, they become in a sense responsible for any actions that that person takes. To paraphrase Colin Powell, we might sum it up as “You surveil him, you own him.”

I recently came across a good analogy for why it’s deceptively hard for security agencies to detect and stop out-of-nowhere terrorist attacks like the Boston bombing—and why mass surveillance isn’t likely to help. It comes from the book The Drunkard’s Walk: How Randomness Rules Our Lives, by the physicist and writer Leonard Mlodinow, in a discussion of Brownian motion.

Brownian motion, you may recall, is the random jiggling of molecules in a liquid or other substance. A dye molecule floating in a seemingly still glass of water will randomly move about, covering about an inch in three hours, buffeted by random collisions with the smaller water molecules that surround it.

What would it take to actually explain the motion of that molecule? This is where the parallel to anti-terrorism efforts comes in. Mlodinow points out, “In any complex string of events in which each event unfolds with some element of