Don't scambait them unless you are fully informed and prepared to deal with any consequences. These scammers are criminals and can get your personal information with a simple N-number search.

If you do want to scambait them, check out some of the protracted exchanges on http://www.419eater.com/html/baiting.htm

FWIW - 419 is the legal code for fraud. When I was working in Nigeria, there were buildings with "No 419" painted on the sides to warn people away from the real estate scammers that would "sell" a house or building with false documents.

Paul A.
Jupiter, FL