An interesting offshoot of the 419 scam was highlighted recently in The Register, an IT insiders journal.
Some recipients of the famous 'I need your confidential help to liberate $16,000,000 from my country' emails are hitting back by engaging the senders in pointless negotiations which exploit a certain lack of familiarity with the language.
Anyone tempted to engage in this sort of baddy-baiting needs to be sure of their personal anonymity, but it seems possible that such reactions may eventually make it difficult for the originators to be sure which, if any, of the responses to their overtures are actually genuine.
I've never seen the internet as a potentially self-regulating environment before..