Let’s be honest it’s not as interesting, or threatening, as most people think.
There have been many talks of sorcery and the NSA invading the public’s privacy, especially those that NSA employees know and who they know. But for the vast majority of individuals, the NSA is not going through your data by hand, the data is simply too massive to go through by hand.
Here is the way the NSA uses your data to spy on you, and in the process ‘strengthen national security’:
It’s a statistics game. We all (should) know that data is gathered concerning what web pages we go to and our search habits. This is how marketers put ads on pages and pretty much every google, yahoo, and facebook account is in this system somehow (every ip address as well).
The key is a mathematical equation. Webpages and keyword searches are first given different weights depending on their assessed threat/danger. Then they multiply the number of times you access the page by that weight to arrive at a score. A regression, measuring ‘danger’ and they are only looking for the .05 outliers. You are under that curve somewhere and they are only interested in those people in the blue, probably even less (as that is still millions of people).
4chan is x amount of ‘points’ and Googling the word ‘gun’ or ‘bomb’ is x amount of points, sure, but a lot of people do those things. Going to the other side of the internet, serial killer chat rooms, animal or child porn websites, secret Al Qaeda websites, or the main login page of the UN office are worth far more points and will get individuals/ ip addresses who go there on a further examination list.
Basically, they use a regression to measure your level of ‘Interest’ and exceeding a predetermined number of ‘interest points’ gets your profile flagged for further examination. Interesting, eh? There is simply too much data to go through in any other way (over 308,000,000 million people, let alone the multiple email addresses).
Once an individual is flagged, the computer spends more time searching for data specifically on them, connecting existing data (a Google or Yahoo account perhaps) to grocery store accounts, face book check-ins, perhaps a library account, flight data, and text messages/ phone history. As much as it can get quickly. Have you Googled yourself recently? There is a lot there. It grabs and sorts what it can; for instance, looking for a school the computer may gather all data available and take the mode of the list.
Anyways, once the additional data has been gathered, it runs it through a more thorough regression. It probably compares phone numbers and email addresses with a massive list of potential and probable threats.
The important thing to understand is that only the tiniest fraction of data will actually be seen by a human. It may be possible for an individual to call up a specific profile (for instance, if they know you), and this is what legislation is trying to put a stop to as we speak.
It is important to remember that we do have a digital fingerprint. And it would be wise to keep that in mind when going through life (especially if you have ambitions, nothing will ruin a political career like a bunch of dick pics). But, we needn’t be concerned that they are spying on us (unless of course you are that .05).