‘We Kill People Based on Metadata’

Supporters of the National Security Agency inevitably defend its sweeping collection of phone and Internet records on the ground that it is only collecting so-called “metadata”—who you call, when you call, how long you talk. Since this does not include the actual content of the communications, the threat to privacy is said to be negligible. That argument is profoundly misleading.

Of course knowing the content of a call can be crucial to establishing a particular threat. But metadata alone can provide an extremely detailed picture of a person’s most intimate associations and interests, and it’s actually much easier as a technological matter to search huge amounts of metadata than to listen to millions of phone calls. As NSA General Counsel Stewart Baker has said, “metadata absolutely tells you everything about somebody’s life. If you have enough metadata, you don’t really need content.” When I quoted Baker at a recent debate at Johns Hopkins University, my opponent, General Michael Hayden, former director of the NSA and the CIA, called Baker’s comment “absolutely correct,” and raised him one, asserting, “We kill people based on metadata.”