Based on the true story about the con-man, counterfeiter, and bank robber John Vogel. FLAG DAY stars Sean Penn and his real-life daughter Dylan Penn. Jennifer Vogel's father John was larger than life. As a child, Jennifer marveled at his magnetizing energy and ability to make life feel like a grand adventure. He taught her so much about love and joy, but he also happened to be the most notorious counterfeiter in US history.