From The New York Times:
A class-action lawsuit about overtime pay for truck drivers hinged entirely on a debate that has bitterly divided friends, families and foes: The dreaded — or totally necessary — Oxford comma, perhaps the most polarizing of punctuation marks.
What ensued in the United States Court of Appeals for the First Circuit, and in a 29-page court decision handed down on Monday, was an exercise in high-stakes grammar pedantry that could cost a dairy company in Portland, Me., an estimated $10 million. […]
Legal history is replete with cases in which a comma made all the difference, like a $1 million dispute between Canadian companies in 2006 or a very costly insertion of a comma in an 1872 tariff law.