In Part One of this series of columns we learned about data and how computers can be used for finding meaning in large data sets. We even saw a hint of what we might call Big Data at Amazon.com in the mid-1990s, as that company stretched technology to observe and record in real time everything its tens of thousands of simultaneous users were doing. Pretty impressive, but not really Big Data, more like Bigish Data. The real Big Data of that era was already being gathered by outfits like the U.S. National Security Agency (NSA) and the UK Government Communications Headquarters (GCHQ) — spy operations that were recording digital communications […]