Edward Snowden has said that he still has more information about the NSA than what he's already leaked, and we're now getting a look at another big piece of that. According to a new set of documents provided to The Guardian, the NSA is using a tool called XKeyscore that is said to be its "widest reaching" system for collecting information from the internet -- one that lets it examine "nearly everything a typical user does on the internet," as one presentation slide explains. That apparently includes both metadata and the contents of emails, as well as social media activity, which can reportedly be accessed by NSA analysts without prior authorization; as The Guardian notes, a FISA warrant is required if the target of the surveillance is a US citizen, but not if a foreign target is communicating with an American.

According to The Guardian, the amount of data collected is so large that content is only able to stored in the system for three to five days, or as little as 24 hours in some cases, while metadata is stored for 30 days. That's reportedly led the NSA to develop a multi-tiered system that lets it move what's described as "interesting" content to other databases where it can be stored for as much as five years. In a statement provided to The Guardian, the NSA says that "XKeyscore is used as a part of NSA's lawful foreign signals intelligence collection system," and that "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." The agency further adds that "every search by an NSA analyst is fully auditable, to ensure that they are proper and within the law."