Read more here: http://www.foxnews.com/politics/2013/12/04/nsa-reportedly-collects-5-billion-cell-phone-location-records-day/
It's definitely happening, so watch out who you're contacting and what you're texting others about.
Also:
"The database and projects designed to analyze it have created a mass surveillance tool for the NSA, allowing it to monitor individuals in a way never seen before.
NSA analysts can look at the data and track an individual’s movements throughout the world. They can then map out the person's relationships with others and expose previously unknown correspondence."
That's creepy...they know where you are! They know all about you!