"The Reader" - dark side of humanity

No movie has impacted me more lately, than "The Reader". After seeing the film, I went home and curled up on the couch feeling rather depressed and helpless. My thoughts were dominated by the dark side of humanity and how we can be so easily beguiled by handsome, affable people.

I had just willingly sat through a movie set in 1950's Germany about the sexual abuse of a teenage boy. Why didn't I get up and ask for a refund?

I know that a relationship between a 30 year-old (Hanna) and a 15 year-old (Michael) is wrong and psychologically damaging. But on the screen they look so happy together; and they are an attractive couple; and don't boys want this kind of thing?; and the theater is full of compliant watchers. This can't be wrong.

Later in the last 1960's Hanna is tried for war crimes linked to the Holocaust and is imprisoned. Okay, involvement in the Holocaust is clearly wrong.

I am left with several unanswered questions. How do I recognize right from wrong when it's not clear cut? How do I stop little wrongs from happening so that they don't get bigger? Is it worth the fight? And should I have walked out of that theater and refused to participate in such a story?