In "Why do Nigerian Scammers Say They are from Nigeria?", Cormac Herley (Microsoft Research, 2012) suggests that scammers make their email deliberately implausible so that only the most gullible respond. I am not sure this is the entire explanation as there are also some scam emails which are very plausible (at least as plausible as late night TV ads for products and services). But perhaps this technique can also be used to warn the same people of their risk. ACMA could send out fake spam emails and any one responding could be sent a warning to look out for similar fakes.
ps: Herley's theory may also explain many political and religious pamphlets. ;-)