Well, one thing is that people don't know the things they might have to hide. Many of the jews murdered in the Holocaust were basically unaware they were even j

Well, one thing is that people don't know the things they might have to hide. Many of the jews murdered in the Holocaust were basically unaware they were even jews, before they started to be persecuted for it. Hannah Arendt was one such case. Unfortunately, this is very common in history. You would never have known that buying a noble title in Bourbon france would lead to the guilotine, nor that being a committed communist would probably get you shot under Stalin. These things are very unpredictable. Being German in early-20th century Montana was dangerous. Being black in 1700's Haiti was, so long as you were free, absolutely not a problem - until it suddenly was. There are countless examples like this. Nobody knows what's coming next.