Metadata: How govt can discover your health problems, political beliefs, and religious practices

Consider calls to single-purpose hotlines: NSA collection of our metadata means the government knows when we’ve called a rape hotline, a domestic violence hotline, an addiction hotline, or a support line for gay teens. Hotlines for whistleblowers in every agency are fair game, as are police hotlines for “anonymous” reports of crimes. Charities that make it possible to text a donation to a particular cause (say, Planned Parenthood) or political candidate or super PAC could reveal an enormous amount about our political activities. And calling patterns can reveal our religious beliefs (no calls on Sabbath? Heaps of calls on Christmas?) or new medical conditions. If, for instance, the government knows that, within an hour, we called an HIV testing service, then our doctor, and then our health insurance company, they may not “know” what was discussed, but anyone with common sense—even a government official—could probably figure it out.

But there’s more, says Felten: By analyzing our metadata over time, the government can separate the signal from the noise and use it to identify behavioral patterns. The government can determine whether someone is making lots of late-night calls to someone who isn’t his spouse, for example. When those calls cease, the government might reasonably conclude that the affair has ended. Metadata may reveal whether and how often someone calls her bookie or the American Civil Liberties Union or a defense attorney. And by analyzing the metadata of every American across a span of years, the NSA could learn almost as much about our health, our habits, our politics, and our relationships as it could by eavesdropping on our calls. It’s not the same thing, but the more data the government collects, the more the distinction between metadata and actual content disappears.