Report: NSA maps out a person's social connections
For almost three years the National Security Agency has been tapping the data it collects to map out some Americans' social connections, allowing the government to identify their associates, their locations at certain times, their traveling companions and other personal information, The New York Times reported. 

N.S.A. Gathers Data on Social Connections of U.S. Citizens
Since 2010, the National Security Agency has been exploiting its huge collections of data to create sophisticated graphs of some Americans’ social connections that can identify their associates, their locations at certain times, their traveling companions and other personal information, according to newly disclosed documents and interviews with officials.  

NSA maps some Americans’ social connections, says report
National Security Agency dips into its database of phone and e-mail info to create complex "social graphs" for foreign intelligence purposes, says a report. Some American citizens get swept up in the effort. 

Notice the use of the word "some" in this news article...  This leads people to think "well, it probably isn't me they are targeting, so it is really ok".  The thing is, while you may not think you are actively engaged in questionable activities, you are linked to someone who is linked to someone who is... making you a person of interest...