The Guardian's Glenn Greenwald today exposed the NSA's "widest-reaching" top-secret Internet spy program, XKeyscore, which can collect "nearly everything a user does on the internet," and confirms Edward Snowden's statement that he could "even wiretap the President."

XKeystone: Searches with no prior authorization. CC:Aravind Sivaraj.

The new revelations include a training slideshow touting everything that XKeyscore can do, including a map of the world-wide system of over 700 servers on 150 sites. This program allows analysts to search, with no prior authorization, through vast databases containing emails, online chats, and the browsing histories of millions of individuals, Snowden's documents show. Social media such as Facebook, including private messages, are totally vulnerable, as is searching HTTP activity by keyword.

The XKeyscore files "shed light on one of Snowden's most controversial statements, made in his first video interview published by the Guardian on June 10," Greenwald wrote: "I, sitting at my desk," said Snowden, could "wiretap anyone, from you or your accountant, to a federal judge or even the president, if I had a personal email." This statement was strongly denied by such U.S. government members as Republican House Intelligence Committee chairman Mike Rogers, who said that Snowden was "lying. It's impossible for him to do what he was saying he could do."

Analysts using XKeyscore and other systems are able to "mine enormous agency databases by filling in a simple on-screen form giving only a broad justification for the search. The request is not reviewed by a court or any NSA personnel before it is processed," Greenwald wrote.

This process is "developing intelligence from computer networks — which the NSA calls Digital Network Intelligence (DNI). According to one file, XKeyscore covers 'nearly everything a typical user does on the internet,' including the content of emails, websites visited and searches, and their metadata. Analysts can also use XKeyscore and other NSA systems to obtain ongoing 'real-time' interception of an individual's internet activity."

While the NSA is by law required to get an individual FISA warrant if they are targeting a 'U.S. person' — no warrant is needed if an American is communicating with foreign targets — XKeyscore gives the technological capability to target a U.S. person without a warrant if the analyst has some identifying information, such as the person's email or IP address. Analysts can also search by name, telephone number, IP address, keywords, the language in which the internet activity was conducted or the type of browser used, Greenwald wrote.

One document notes that this is because "strong selection [search by email address] itself gives us only a very limited capability" because "a large amount of time spent on the web is performing actions that are anonymous." The program can search "every email address seen in a session by both username and domain", "every phone number seen in a session (e.g., address book entries or signature block)" and user activity — "the webmail and chat activity to include username, buddylist, machine specific cookies, etc.". The analyst enters the individual's email address into a simple online search form, along with the "justification" for the search and the time period for which the emails are sought.

As a top secret 2010 guide for training NSA analysts under the FISA Amendments Act of 2008 explains, analysts can begin surveillance on anyone by clicking a few simple pull-down menus designed to provide both legal and targeting justifications.

XKS is collecting so much data that the NSA can only store it for a few days at most. A 2007 NSA report estimated that there were already 850 billion "call events" collected and stored in the NSA databases, and close to 150 billion internet records, with 1-2 billion records added every day. The NSA has created a multi-tiered system for storing "interesting" content in other databases. In 2012, there were at least 41 billion total records collected and stored in XKeyscore for a single 30-day period.

Reporters raised the new Guardian revelations to White House press spokesman Jay Carney on Wednesday, who said in a testy exchange that he did not know whether the administration ever briefed the U.S. Congress about XKeyscore. He claimed that the Guardian article contained inaccuracies, but did not specify any.