It was my understanding (perhaps incorrect?) that these laws prohibited even private party cash transactions, not just merchant transactions.

Assuming correct (if not, wait a little while and it probably will be), this same law could likely apply to anonymous virtual coin transactions between private parties.

Anyway, at the moment I don't see much of a movement toward banning virtual currencies, and this is indeed somewhat surprising relative to expectations a few years ago, although I think the winds could shift on that, especially with respect to untraceable virtual currencies. Nothing is certain though.