. >> safer: stephen greenspan is a university of colorado professor who writes and lectures on gullibilityences that not reading the fine print or buying something on a tip from your brother-in-law are bad ideas and that older people are particularly vulnerable to a friendly pitch from a conman. in most of the great moments of gullibility in history, the perpetrator seems to target a particular group, correct? >> yes. there have been mormon ponzi schemes targeting mormons or fundamentalist christians. madoff mostly was aimed at jews 'cause he was a prominent jewish philanthropist. so, yes, there is this affiliation aspect of it because we tend to trust our own kind. >> here in 1919 as charles ponzi self-styled financial wizard loafing at his boston mansion with his lovely wife and proud and adoring mother. >> safer: mr. ponzi himself promised fellow italian immigrants he could make them rich trading in postal reply coupons, sort of the pre-paid phone cards of the day. ponzi went to prison and died a pauper. >> i went out looking for trouble. i found it. >> safer: but his name lives on for