It's unbelievable how many online scams, or e-mail scams, these people find. You know, the e-mails with the rich uncle you never knew about who died in Nigeria and left you millions. Or the e-mails who offer you a job of $100 per hour just to make some bank transfers. If only these people would use their imagination for a good, honest enterprise, they might actually get some place.
A new way to use the same old trick is on web chats now. They find the prey in some country, present themselves as rich Americans working or traveling abroad, who all of the sudden need some urgent cash for something, and since you're their friend, maybe you'll offer to help... There are actual websites presenting the portfolio of pictures these people use in their e-mails and communications with their victims.
It's also surprising that you actually find websites all over with victims of these people.
I would expect them to trick some not very Internet and economy savvy people from developing countries, but not from the US. However, since Bernard Madoff was able to trick so many financially knowledgeable people, I guess the Nigerian stuff is not that extraordinaire.