One might have to be a complete moron to send money to these men. Unfortunately, or fortunately depending on the perspective, the entire world is full of morons. All these sc are called 419's for the Nigerian penal code exemption for the offense. It's estimated that it accounts for 1/3 of the Nigerian GDP together with the figure reaching into the tens of billions over the last 20 years.
It's simply greed along with stupidity, a common mix found across the species, which is accountable for this and it's not going off. Sc are as old as the human race.
If you want to read some really funny stuff, go to this site.
Http://www.419eater.com/