Whether we consider Nazi Germany or Abu Ghraib prison, there were many people who observed what was happening and said nothing. At Abu Ghraib, one photo shows two soldiers smiling before a pyramid of naked prisoners while a dozen other soldiers stand around watching passively. If you observe such abuses and don't say, "This is wrong! Stop it!" you give tacit approval to continue. You are part of the silent majority that makes evil deeds more acceptable.