New research from Cormac Herley of Microsoft Research* suggest that the outrageous stories and poor writing in these emails serve the purpose of weeding out all but the most gullible of targets. In other words scammers take pride in their poor work because those who respond when something is so clearly off are the most likely to continue falling for the trap. I suppose it is another example of the virtual world and the physical world becoming ever more similar; as Amarillo Slim once said, "If you're at a poker table and don't see the sucker, it's you."
There are obvious legal implications of these situations. Internet scamming, no matter how gullible the rube, is illegal. That said, cross-border police action specifically, and policing of the internet, more generally, obviously come with difficulties. However, as suggested in an Economist article on the topic, there could be an economic/social solution:
One implication of Mr Herley's work is that a little bit of public-spirited scam-baiting—wasting the fraudsters' time by pretending to be a potential victim—can increase the scammers' costs and undermine their business model. For those with some time to spare, joining a cyber-posse may offer an amusing way to make the world a safer place.
*Who Do Nigerian Scammers Say They Are From Nigeria- research.microsoft.com/pubs/167719/whyfromnigeria.pdf