The New York Times carries a story about Nazis moving through Amsterdam with ready-made lists of enemies and Jews, rounding them up and having them shot en masse.
How are the Nazis ready with so much information about the identities and locations of the people they wanted to kill immediately?
They made extensive use of IBM Hollerith machines. IBM make it possible for the Nazis to sort through massive amounts of information, picking out just the bits of data they wanted most.
