The Chocolate War, Robert Cormier, 1974. Small-town freshman's refusal to sell candy for his manipulative school earns him the ire of headmaster and vengeance of underground student group, the Vigils. He is harassed, beaten, ostracized, and left alone.
The book was fought ostensibly for negativism, violence, language and sexual activity - but perhaps more realistically for anti-authority worldview.