Anyone read REAMDE by Neal Stephenson? http://en.wikipedia.org/wiki/Reamde

The core game that the book describes is written to embrace the RMT'ers as a mechanism for spreading wealth from rich western countries to the poorer nations, and the game as described had mechanisms to support such.

Reading that story, it does explore an interesting angle on the whole RMT thing. Rather than trying to ban, rather, embrace it as a legitimate practise that is regulated in its own way (ie. no chat log spamming, and really there's no need to, if it's legal).