Email addresses on nanny do get sold.
I know of at least one wiz that admitted to selling them a year or so ago.
Unfortunately it was one high enough to access most anyone's email address.
I won't be listing my new one there.
This seems very odd, what on earth would anyone want those emails for? Selling toy swords???
Seriously, I'd say that people playing Nanny are probably some of the least likely people to fall for spam. And how many different correct addresses could you possibly get???