There's good reason, in an money making online game, for not letting a person own and play more than one account. The collusion* in the above example is between the player-characters. So even though it's just one person, the player characters are secretly working together.
Imagine coming into a real money, online poker table where a few seats are filled by the same player playing several player characters. The advantage gained by even playing one additional seat, and knowing what cards they held would be tremendous (this is why I never played online poker, I can't think of a table where this wouldn't be the case). To me, the most important feature of one of these games, if i were to play, would be to what extent they could guarantee that people weren't working together. Honestly, I don't see how they could, as anyone could just call work together on the phone/skype, etc.
An example of PC collusion in our experience, would be when someone queues an extra, opposite faction character for WSG, grabs the flag it, then proceeds to suicide in mid — giving his team the first cap. I've even seen people exploit this for flag return achieve
Anyway, the more that I think about it, the more I think a one account per person limit might be good. The similarity between poker and the AH are actually quite striking when you think about it.
*I am not speaking of the legal term "collusion", just the regular word.