Why The “It’s Just Metadata” Argument Is False
One of the common defenses that has been trotted out over the past week to push back against criticism of the National Security Agency’s practice of collecting phone records for later review has been that all the NSA is collecting is so-called “metadata.” Essentially, this argument tells us not to worry because the NSA isn’t actually listening in to our phone calls, it’s just collecting records of who talked to who, when and for how long. However, as former Sun Microsystems engineer Susan Landau told the New Yorker, metadata can tell analysts much more than even a wiretap can at times:
The public doesn’t understand,” she told me, speaking about so-called metadata. “It’s much more intrusive than content.” She explained that the government can learn immense amounts of proprietary information by studying “who you call, and who they call. If you can track that, you know exactly what is happening—you don’t need the content.”
For example, she said, in the world of business, a pattern of phone calls from key executives can reveal impending corporate takeovers. Personal phone calls can also reveal sensitive medical information: “You can see a call to a gynecologist, and then a call to an oncologist, and then a call to close family members.” … Metadata, she pointed out, can be so revelatory about whom reporters talk to in order to get sensitive stories that it can make more traditional tools in leak investigations, like search warrants and subpoenas, look quaint
Metadata, Landau noted, can also reveal sensitive political information, showing, for instance, if opposition leaders are meeting, who is involved, where they gather, and for how long. Such data can reveal, too, who is romantically involved with whom, by tracking the locations of cell phones at night. (emphasis added)
The New York Times’ Quentin Hardy expands on that argument:
For some communications, metadata matters more than content. “A call to a suicide hot line, Alcoholics Anonymous, or a gay sex chat room at 2 a.m. are all more sensitive” than the actual message, said Christopher Soghoian, principal technologist at the American Civil Liberties Union. “You can text political donations. The metadata shows your political leanings, the content just shows the amount you gave. Calling a cell tower away from my house in the middle of the night indicates I’m not sleeping at home.”
“Metadata is the least protected form of communications information, and that is a shame,” he said. “You just have to say it’s important to an ongoing investigation.”
To place the information in a more historical context, Kieran Healy takes us back to the years before American Revolution:
I have been asked by my superiors to give a brief demonstration of the surprising effectiveness of even the simplest techniques of the new-fangled Social Networke Analysis in the pursuit of those who would seek to undermine the liberty enjoyed by His Majesty’s subjects. This is in connection with the discussion of the role of “metadata” in certain recent events and the assurances of various respectable parties that the government was merely “sifting through this so-called metadata” and that the “information acquired does not include the content of any communications”. I will show how we can use this “metadata” to find key persons involved in terrorist groups operating within the Colonies at the present time. I shall also endeavour to show how these methods work in what might be called a relationalmanner.
The analysis in this report is based on information gathered by our field agent Mr David Hackett Fischer and published in an Appendix to his lengthy report to the government. As you may be aware, Mr Fischer is an expert and respected field Agent with a broad and deep knowledge of the colonies. I, on the other hand, have made my way from Ireland with just a little quantitative training—I placed several hundred rungs below the Senior Wrangler during my time at Cambridge—and I am presently employed as a junior analytical scribe at ye olde National Security Administration. Sorry, I mean the Royal Security Administration. And I should emphasize again that I know nothing of current affairs in the colonies. However, our current Eighteenth Century beta of PRISM has been used to collect and analyze information on more than two hundred and sixty persons (of varying degrees of suspicion) belonging variously to seven different organizations in the Boston area.
Healy then goes through a detailed analysis of actual British intelligence that had been gathered regarding the relationships among certain people in the Boston area in the early 1770s, and comes to this conclusion:
From a table of membership in different groups we have gotten a picture of a kind of social network between individuals, a sense of the degree of connection between organizations, and some strong hints of who the key players are in this world. And all this—all of it!—from the merest sliver of metadata about a single modality of relationship between people. I do not wish to overstep the remit of my memorandum but I must ask you to imagine what might be possible if we were but able to collect information on very many more people, and also synthesizeinformation from different kinds of ties between people! For the simple methods I have described are quite generalizable in these ways, and their capability only becomes more apparent as the size and scope of the information they are given increases. We would not need to know what was being whispered between individuals, only that they were connected in various ways. The analytical engine would do the rest! I daresay the shape of the real structure of social relations would emerge from our calculations gradually, first in outline only, but eventually with ever-increasing clarity and, at last, in beautiful detail—like a great, silent ship coming out of the gray New England fog.
Essentially, using nothing more than information about who knew whom and who else those people interacted with, you can construct someone’s entire social network. That’s something that can be used to track down terrorist cells and even members of drug gang and organized crime families. It’s also something that could theoretically be used to track down a group of government dissidents or people who would simply choose to keep their social relationships private. And you can do all of that without actually listening in on any of their conversations using the right statistical analysis tool. So, the “it’s just metadata” argument is invalid because it assumes, incorrectly, that metadata itself isn’t important. Indeed, it may be the most important information of all.