This is a hard question.
The world is full of poisonous thought.
Infants must be sheltered from anything that robs them of self respect or causes them to be angry and mean.
But by the time a person leaves high school they are immersed in the complete real world, it is not really good that the sheltering due an infant continue till adulthood when all access is open and the person is fair game to every kind of cheat.
The best idea is probably to pay a lot of attention to the child and stay ahead of the introduction of bad ideas with discussion of the bad ideas more than blocking them from view.
This is hard to do , the companies that produce television and video seem enmeshed in a vast conspiracy to circumvent parental guidance and exploit the young.
Also ,as has happened to me , a parent might find that his child is more clever than the parent and can find his own ways around blocking , refute argument and come up with his own bad ideas.
I take some comfort in the notion that the child in particular that is clever vs his guardian might also be clever enough against the outer world to avoid most exploitation.
