This is how Hitler and the Nazis found where the Jews were:
http://www.amazon.com/gp/product/0914153102/ref=lst_llp_sl-1?ie=UTF8&coliid=I2XHFJ652N7NUH&colid=3QEHOQMYACE8C
That book was given to me as a gift on my Bat Mitzvah.
Excellent book. I gave my dad the audio version and he could only listen to 1/2 or so, he was so disturbed at what he was hearing. He was so mad because he had thought for all these years IBM was a ‘pure’ American success story. He directed his IRA managers to unload any fund that had any IBM stock in it and never has held any since.