I watch his TED talk once a year about the psychology of evil and make me aware of the seven rules that he has established.

7 Processes that Grease the Slippery Slope of Evil

1. Mindlessly taking the first small step.

2. Dehumanization of others.

3. De-individuation of self (anonymity).

4. Diffusion of personal responsibility.

5. Blind obedience to authority

6. Uncritical conformity to group norms

7. Passive tolerance of evil through inaction or indifference

https://www.ted.com/talks/philip_zimbardo_the_psychology_of_...