With the rapid emergence of digital devices, an unstoppable, invisible force is changing human lives in ways from the microscopic to the gargantuan: Big Data,  a word t hat was bar ely used a f ew years ago bu t now govern s the day for m any of u s from th e moment we a waken to t he exting uishing o f the fin al late-e vening li ght bulb. This  massive gat hering and a nalyzing of  data in re al time is allo wing us to  not only  address some of  humanity  biggest challen ges but is a lso helping cre ate a n ew kind of pl anetary  nervous sy stem. Yet as Edward  Snowden and  the rel ease of the Prism  documents hav e shown, t he accessib ility of al l these d ata com es at a steep  price. The Human Face of Big Da ta capture s the prom ise and peril o f this extraord inary k nowledge r evolutio n.　　With the rapid emerg ence of digital device s, an unsto ppable,  invisib le forc e is changing h uman liv