Edward Snowden's critics, inside and outside the U.S. government, regularly claim that his theft of classified documents is damaging to national security in part because officials must assume a worst-case scenario: that he took a couple million documents, and that China, Russia, or others gained access to all of them.

Michael Kelley's latest article reports on questions relevant to this critique. Officials claim that Snowden "touched" almost 2 million files in the course of carrying out his duties as an NSA subcontractor, he notes, and according to Lieutenant General Michael Flynn of the Defense Intelligence Agency, “Everything that he touched, we assume that he took."

There's something I don't understand about this "assume he took everything" approach.*

On one hand, I can see the logic in assuming the worst about what secrets are now known to rivals or enemies. And I see how countermeasures could prove expensive. Even if you believe, as I do, that the benefits of Snowden's disclosures outweigh the costs, it's only fair to acknowledge that there are costs, and this is one.

But another part of me thinks the following: that if Snowden could steal all these documents undetected, without intelligence officials knowing what he took even after the fact, then assuming that their contents are unknown to our enemies was foolish all along, because Snowden doesn't possess any unique, superhuman ability to steal documents. If he pulled this off, someone else could've pulled off something similar, quietly selling the stolen secrets to our enemies, rather than passing them off to foreign journalists and alerting the United States government to the theft.