Interesting question to think "lost" money or anything is theft. There have been treasure hunters who spend millions of dollars to hunt in the oceans around the globe who are looking for other peoples "lost" treasures. Some have even been brought to court and forced to pay the bloodline of the so called owners treasure lost at sea hundreds of years ago. If you find and Indian arrow head in the woods. Is it theft to take it? How much time has to pass before something is truly considered "lost"...