By now we know the National Security Agency watches nearly everything on the Internet, with a few exceptions. But apparently Edward Snowden was able to steal the information he did because the NSA failed to monitor its internal networks.

A security failure allowed Snowden, the former contractor now living in asylum in Russia, to move around the NSA's computer system and steal an unimaginable trove of top-secret documents without leaving a trail behind, senior administration officials told The New York Times' Mark Mazzetti and Michael Schmidt

Officials have literally no idea what Snowden stole, or how much, or from where, because computers at the NSA's Hawaii office, where Snowden took the information, were "not equipped with up-to-date software that allows the spy agency to monitor which corners of its vast computer landscape its employees are navigating at any given time," according to Mazzetti and Schmidt. The NSA wasn't tracking its own employees internal movements, while the NSA was tracking the digital movements of millions worldwide. Oh, good. 

In 2011, in the wake of the Wikileaks scandal, President Obama ordered federal agencies to "better safeguard their classified secrets," among other things. The executive order was to protect the government from the kind of internal leaks caused by Chelsea Manning, and eventually Edward Snowden.

So what happened in the two years between both leaks? The NSA lolly-gagged upgrading their security system. In theory, the executive order implemented immediate change. In practice, the NSA was behind, and Edward Snowden took advantage of the opening

Officials said Mr. Snowden, who had an intimate understanding of the N.S.A.’s computer architecture, would have known that the Hawaii facility was behind other agency outposts in installing monitoring software.

According to a former government official who spoke recently with Gen. Keith B. Alexander, the N.S.A. director, the general said that at the time Mr. Snowden was downloading the documents, the spy agency was several months away from having systems in place to catch the activity.

Now the investigation that began months ago into Snowden's leaks, separate from the review of government surveillance practices, which Obama will review soon, has hit a wall. “They’ve spent hundreds and hundreds of man-hours trying to reconstruct everything he has gotten, and they still don’t know all of what he took,” one official told the Times. “I know that seems crazy, but everything with this is crazy.”