With these vast amounts of data being collected, it's easy to understand why NSA would need a data center in Utah with a capacity measured in zettabytes. And it's also easy to see why privacy advocates would be concerned about the potential for abuse of the data.
Setting policy aside and focusing purely on capabilities, the NSA has the technology in hand to create detailed maps of the relationships between hundreds of millions of people inside and outside the US, and the means to dip into the communications that make up those relationships. It also has the ability to safeguard that data from casual access by people not cleared to use it. And it likely has the ability, when the need arises, to defeat the most basic means used to protect communications from surveillance.
Even with the giant data center the agency is constructing, it's still not going to be able to capture the entirety of Internet traffic. But the NSA doesn't have to capture all of it to have a view of what nearly anyone is up to—the metadata collected from traffic alone is enough to gather significant information about individual's online activities.
The question is not, then, whether the NSA can or can't uncover nearly every aspect of an individual's digital life and go all "Enemy of the State" on someone. The question is whether the safeguards in place that govern their use of that capability are sufficient to protect against abuse. There are certainly layers of compartmentalization within the NSA's internal databases, but just how strict the safeguards are isn't known outside the NSA.
Director of National Intelligence James Clapper and other US officials say that the law guarantees that data "cannot be used to intentionally target any US citizen, or any other US person, or to intentionally target any person known to be in the United States." But Edward Snowden's statements would suggest that the law isn't enough to prevent government contractors from using the NSA as their personal search engine.
read the complete article: http://arstechnica.com/information-technology/2013/06/what-the-nsa-can-d...