out tens of thousands of dollars, his childhood dreams destroyed, california teacher karl ryll was now warning others about treasure hunter dennis standefer. a man he says who conned him, betrayed him, at the very time karl's father was dieing. >> my main goal was to make sure no one else got ripped off by him. and so, i figured i could at least do that. >> reporter: using e-mails and phone calls, ryll contacted everybody he could find connected to the treasure hunter, a blitz designed to cut off standefer's money supply. >> i was finding people that went back 30 years that he had ripped off. >> reporter: convinced his efforts had succeeded, karl sunk slowly back into an otherwise ordinary life, believing his bitter experience with standefer