More important, there appears to be consensus that too much is classified, and for too long. As those labels proliferate for material whose release wouldn't threaten national security, it can make even the most assiduous handler of classified information see less why the distinctions matter. Worse, leaking is often an instrument of official government policy. This doesn't always entail classified information, but the more it becomes common practice, approved or initiated at the highest levels, to leak information rather than to out it directly, the harder it is to make the general ethical case that secrets are meant to be kept. Put together a culture of excessive classification with one of strategic, "approved" leaking and once again there's the worst of both worlds.

This suggests that classification might be more effective if applied as the exception rather than the rule, and only to small, specifically enumerated classes of information whose release could impact the national security in highly specific ways: intelligence sources (like who told the government a secret), intelligence methods (like how the government is able to quietly surveil an enemy), and nuclear bomb secrets. (Even the latter category appears overprotected, given the amount of information already in the public domain. The biggest bottleneck against nuclear proliferation may lie in the physical material rather than in know-how.)

Finally: a lesson for any group or institution wanting to keep a major, identity-defining secret: the distance between the face one presents to the world, and the face presented inward to oneself, cannot no longer become too great. Like water finding its level, the inward face will become known. The truth, or at least more of its constituent parts, will out. In the big picture, that's a good thing. Those who have the most to fear from an open environment are ones with closed agendas, for whom public debate is a threat rather than an opportunity. Long-term strength lies in persuasion grounded in fact, rather than on carefully constructed artifice.

Jonathan Zittrain is an Internet law professor at Harvard Law School and a cofounder and faculty codirector of Harvard's Berkman Center for Internet & Society.