It's a good analogy because people are people. The auschwitz guards are just brothers, fathers, husbands like any of us.
The situation turned them into monsters. Not all of them, some of them were just going along with it to keep the peace so to speak.
My guess is you've got the same situation with the FBI, normal everyday People sucked into a corrupted organisation believing that the organization is right and correct, going along with everything that is requested of them blindly following the orders until one day they go, hold on that's not right..... But what do you do if you become a whistle blower, if you resign, it's a big change, a big decision.
You risk ostracisation from a career you love. You rest losing your income and pension.
You may even be risking your life.