What junk.
Just believe that every cell phone call, text, and email is captured by the NSA. Also every conversation you have near a mobile phone even if it is “off.”
Their problem is not capturing the date, it’s screening the data for analysis because there is just too much for any human to screen.
Big data not only aggregates disparate data sources and types, it also multiplies it. Regular data bases are relational; data stores build cubes that rely on redundancy to increase speed and depth of searches. It’s not intuitive, but more data aids searching as long as you have the computing power.
Data is not screened; it’s built into a self-referential framework that provides almost instant answers to queries that would bring the most powerful traditional databases to a screeching halt. Welcome to the Borg.