But if you delve into that history even more, you'll note that it was accompanied by a pervasive sense of dread and fear even amongst those who were not being persecuted. In Nazi Germany, for instance, it was not just the Jews who lived in terror of the Stasi (edit: mixed up my history, not Stasi, but the "death squads" -- the Stasi came after the war, but even more feared), but all German citizens in general. The reason was probably that the Stasi made no attempts to hide their activities, just as the various Islamic groups and Mexican drug gangs don't today. Publicity of their acts to spread terror is the very tool these folks rely on to exert their control.

People who draw parallels between the actions of today's intelligence agencies and the agencies of oppression of yesteryear uniformly miss out on this key difference.