A collective effort would be easy enough to completely squash the 419 scam.
The thing to do would be to have everyone respond with bogus information. They would be working overtime sifting through the crap. Imagine having to look through ten thousand bank accounts numbers with the likelihood of any one of them being valid as next to nothing. It would throw up red flags at all the banks and point straight at the nigerians doing it.
There is a web site where this guy responds to spam and tries to jack with them and string them along... He really laid it on thick with one nigerian scam artist - »www.thespamletters.com/