Three months after whistleblower Edward Snowden fled the US, the NSA still doesn't know the extent of the data he stole.

NSA Still Doesn't Know Amount of Data Stolen by Snowden
A picture of Edward Snowden, a contractor at the National Security Agency (NSA), is seen on a computer screen displaying a page of a Chinese news website, in Beijing in this June 13, 2013 (Reuters)

Despite claim from US officials that the Edward Snowden leaks are in hand, sources within the National Surveillance Agency (NSA) now claim that over three months after Snowden fled his home in Hawaii with a cache of top secret documents, the agency still doesn't know the extent of what he stole.

Snowden fled his home in Hawaii on 20 May, before arriving in Hong Kong and handing over some of the leaked documents to journalists for the Guardian and Washington Post newspapers. Over the last two-and-a-half months numerous documents have appeared in the media relating to the covert surveillance programmes operated by the NSA in the US and their counterparts in the UK, France, Australia and elsewhere.

Two separate sources speaking to NBC News say the NSA is "overwhelmed" trying to acssess the scale of the damage caused by Snowden. The sources claim the NSA had poor data compartmentalisation allowing Snowden, who was a system administrator, to "roam freely across wide areas." The sources claim that Snowden, using a "thin client" computer, remotely accessed the NSA data from his base in Hawaii.

Investigators

These revelations are at odds with what the US government has been saying about the situation. As early as the beginning of June, NSA investigators claimed they knew how Snowden had stolen the information - using thumb drives - and that they "know how many documents he downloaded and what server he took them from."

However later that month deputy national security advisor Ben Rhodes rebuffed these claims saying the NSA still didn't know the extent of the Snowden leaks.

Then at last month's Black Hat hacker conference in Las Vegas, the NSA chief Keith Alexander sought to reassure those worried about the amount of data Snowden stole, saying: "We have tremendous oversight over these programs. We can audit the actions of our people 100 percent, and we do that."

Doubt

The NBC report however puts this into some doubt, and considering Alexander is planning on pushing ahead with replacing 90% of the agency's system administrators with computers, it would suggest the amount of oversight the NSA really has is a lot less than claimed.

NBC's sources say that Snowden is sitting on unreleased information which includes details of data collection by US allies such as the UK, Canada, Australia and New Zealand.

"These English-speaking allies, known along with the US as the "Five Eyes," are critical to US intelligence efforts," NBC reports.