There's a lot of great work on "evil." The Lucifer Effect is the starting point, and there's an awesome book about how some normal soldiers transformed into murderers. Ordinary Men: Reserve Police Battalion 101 and the Final Solution in Poland. We can see what's called the banality of evil today, with TSA:
Banality of evil is a phrase coined by Hannah Arendt and incorporated in the title of her 1963 work Eichmann in Jerusalem: A Report on the Banality of Evil. It describes the thesis that the great evils in history generally, and the Holocaust in particular, were not executed by fanatics or sociopaths, but rather by ordinary people who accepted the premises of their state and therefore participated with the view that their actions were normal.
Mark Bennett collects some revealing quotes. Although I don't care if TSA grabs my junk, many Americans do. They find it immoral. Yet TSA agents defend their conduct: "We're just doing what the government has told us to do."
They don't want to play with your fat rolls or grab your junk. They would even prefer not to. Who can blame them? Take a look around an airport - especially in a place like Dallas. Would you want to touch those people? (And of course you are those people to someone else.)
TSA agents, however, will do the unpleasant and evil task because they have a job to do.
Most evil is so banal. It's boring. The German guards didn't want to murder Jews. They did it, though. And everyone we know would have been guards, too, had we lived in Germany during World War II.
What's the take-away of the literature on evil? Government must remain small. The banality of evil exists because people will do what the State tells them to do. Evil becomes ho-hum, just another punch-the-clock-part-of-my-day. Keep the State small, and you'll reduce aggregate evil.