By the summer of 2001, federal investigators were closing in on what at first appeared to be an unusual fraud case tied to a fast-food promotion. The tip was strange enough on its own. A national game, run by one of the most recognizable brands in the world, had allegedly been compromised for years without detection. What unfolded was not a case of a few isolated cheats or opportunistic players. It was a coordinated scheme that quietly redirected millions of dollars in prizes over more than a...