Somebody's already linked China's credit score shenanigans which is a good example; I'll also chime in by saying there's been actual books written how IBM (and big data of that time) was a direct factor in making the Holocaust happen (https://en.wikipedia.org/wiki/IBM_and_the_Holocaust). Once when "undesirables" (like myself) can be sorted by any widespread metric ... it's too easy to be used as a weapon for more nefarious means.