Parents often claim that they didn't know their child was into drugs, hanging out with the wrong kind of friends or committing crimes when everyone around is aware of all this
The monster dad in Germany, who had imprisoned his daughter in a basement for 24 years and sexually abused her, shocked the world.
But even more shocking was the fact that his wife, who lived upstairs in the same house, never noticed this.
If, for 24 years, a woman did not see that her husband was up to some dubious activity in the same house, it's probably because she didn't want to confront him, discover something awful and end up destroying her marriage and smug suburban family life.
Many will play blind, deaf and dumb if they fear that bringing up an issue that's making them uncomfortable will have a disturbing effect on them, or force them to take a difficult decision.
The tragic German episode is an extreme case. But how many times do we come across people who have been flagrantly carrying on extra marital affairs, and the spouse claims not to have noticed, till the affair threatens their marriage.
Then they weep and accuse their family and friends of hiding the truth from them, when in fact, they may have been directly or indirectly warned, but they ignored the signs and alerts, in the belief that if they didn't ask questions, the problem would go away.
They are afraid of destroying their marriage and the comfortable status quo of their family, and their place in society. They are afraid of what people will say, and in the process, cause themselves and their families more harm.
Parents often claim that they didn't know their child was into drugs, hanging out with the wrong kind of friends or committing crimes when everyone in the neighbourhod is aware of all this. If someone tells them, they will turn on the informer and accuse them of maligning the kid.
When the rebellious kid is caught, hurt or killed, the parents will wail and say how everyone around betrayed them. But they will not question the kid, in case he or she runs away from home, or turns around and accuses the parent of not trusting them.
They'd rather have self-destructive kids at home, than have them leave, and face charges of being bad parents.
Many also ignore illicit activity in their neighbourhood - felling of trees, bootlegging, illegal construction and wife-beating, because they don't want to get into any lafda.
But when it blows up in their faces, they will innocently say, "We didn't know."
On a larger scale, persecution of minorities takes place blatantly, because society turns a blind eye to this. They just don't want to get involved, be held responsible, and be forced to take an unpleasant decision or endanger themselves.
Coming back to the girl imprisoned in the cellar, her mother will have to lead the rest of her life with the terrible consequences of her complicity with her husband's heinous deeds. And she could have, if only she weren't such a coward, to have prevented it.