It is rude to desecrate a grave.
James' high school bully Andy was hit by a bus and buried in a local cemetary.
James wants closure on his resentment towards Andy.
James writes a letter to Andy about all of his resentment, then burns it.
James knocks over Andy's tombstone and pees on his grave.
James feels like writing the letter helped him let go of high school.
James is caught by the caretaker and hauled off to jail.