Smith was seated comfortably in his living room one evening when a rock crashed through the window and landed at his feet, amidst a shower of splintered glass. To the rock was attached a note: "Unless you pay us $10,000 according to instructions, we will kidnap your wife."
After some thought, Smith sat down at his desk and penned a reply:
Your rock of this date has been received. I don't have $10,000 at this time. However, keep in touch, as your proposition interests me.