The ever forgetful Cliff Janeway (your bookseller friend, most recently from Problem Set 22) calls you one afternoon from the airport in Albuquerque, where he just got off a plane to visit some local booksellers. He is frantic because he left his checkbook on the seat next to him when he left the plane. He is pretty sure that his debit card was stuffed inside the check- book, and he is sure that his personal identification number is written on the inside cover of the checkbook. His account has about $12,000 in it because he planned to purchase several expensive books while in Albuquerque. He wants to know what he should do. Does he have anything to worry about? For example, what would happen if the thief used the debit card to spend $3,000 on the day that the card is stolen, but Cliff doesn't report the theft for two weeks? Would it be different if the $3,000 charge occurred a week after the theft instead of the next day? Why should that matter?