As the IC and NSA have stated previously, the implication that NSA's collection is arbitrary and unconstrained is false. NSA's activities are focused and specifically deployed against - and only against - legitimate foreign intelligence targets in response to requirements that our leaders need for information necessary to protect our nation and its interest. Public release of this classified material about NSA collection systems, without context, does nothing more than jeopardize sources and methods, and further confuse a very important issue for the country. Although it is impossible to provide full details of classified programs and still have them remain effective, we offer the following points for clarification:
XKEYSCORE is used as part of NSA's lawful foreign signals intelligence collection system. By the nature of NSA's mission, which is the collection of foreign intelligence, all of our analytic tools are aimed at information we collect pursuant to lawful authority to respond to foreign intelligence requirements - nothing more.
Allegations of widespread, unchecked analyst access to NSA collection data are simply not true. Access to XKEYSCORE, as well as all of NSA's analytic tools, is limited to only those personnel who require access for their assigned tasks. Those personnel must complete appropriate training prior to being granted such access - training which must be repeated on a regular basis. This training not only covers the mechanics of the tool but also each analyst's ethical and legal obligations. In addition, there are multiple technical, manual and supervisory checks and balances within the system to prevent deliberate misuse from occurring.
Our tools have stringent oversight and compliance mechanisms built in at several levels. One feature is the system's ability to limit what an analyst can do with a tool, based on the source of the collection and each analyst's defined responsibilities. Not every analyst can perform every function, and no analyst can operate freely. Every search by an NSA analyst is fully auditable, to ensure that they are proper and within the law.
These types of programs allow us to collect the information that enables us to perform our missions successfully - to defend the nation and to protect US and allied troops abroad. (For example, as of 2008, there were over 300 terrorists captured using intelligence generated from XKEYSCORE.)
Continuous and selective revelations of specific techniques and tools used by NSA to pursue legitimate foreign intelligence targets is detrimental to the national security of the United States and our allies, and places at risk those we are sworn to protect - our citizens, our war fighters, and our allies.