In "Fahrenheit 451," what does Montag learn about the excessive cruelty of young people as he is making his escape?

We learn about the cruelty of the young early on. Clarisse comments on how many teenagers die in car accidents, get into vicious fights, and kill themselves by overdosing. Toward the end, as Montag flees, the cruelty of society is illuminated. Because the authorities cannot catch him, they sacrifice an innocent man by posing him as Montag and setting the hound on him. He is attacked and dies on live television.