But metadata is more powerful than most people realize. For instance, something as simple as recording Facebook “likes” and website clicks can reveal a person’s religious and political views, economic standing, sexual preference, personality, mental health, ethnicity, use of addictive substances, and more. The ability to characterize groups by these traits might tempt some in the government to cross the line from finding terrorists to targeting groups because of their political leanings.

Because of the scale and connectedness of data collection and the inability of today’s institutions to squarely face the privacy issues involved, we strongly back a new approach to data privacy that we’re working on here at MIT’s Media Lab. It puts individuals in control of their personal data, allowing them to determine who can possess their data, how it can be shared, redistributed, and disposed of.

Each citizen would have a personal data store, like an email inbox, that would let them see where data about them goes and how it is being used. The NSA could still get a court order allowing it to use a person’s metadata to track terrorists, but at least an individual could see that something is happening – rather like seeing a police cruiser patrolling the neighborhood. The big difference from now is that individuals could see which companies or government agencies were using data about them, and control these groups’ access to that data.