Sports fans can be a savage lot. When it comes to cruelty, is there any group more relentlessly inventive? Chanting in unison, they pick at the heart of the enemy. But in my book, there's one chant more brutal than any other. It's worse than insulting someone's family, worse than hurling the most unspeakable epithet, and worse than mocking a personal handicap. This one cuts the deepest.