Does this man believe we should have legal regulation of game economies? Oh wow.
Assume an economy can be sized... so it's a $100m economy, or a trillion-$ economy, etc.
Connecting economies together obviously causes them to impact each other. So long as games are connected just to the US economy, and it is much, much larger than any game economy, the impact on the "real" economy is nil.
What about a much smaller real economy? Connect an economy the size of Eve or WoW to one the size of Zimbabwe. Suddenly, events in the game can have very real macro-economic effects on the "real economy". For example, uncontrolled creation of "wealth tokens" can lead to inflation, and contaminate the real world just in the same way as currency fluctuations impact the real world.
Banks can create money, and they are regulated. If virtual economies can create money on a scale large enough to disrupt the real economy, shouldn't they be regulated too?
I'm not saying the answer is obviously one way or the other, but to dismiss the question with an "Oh wow" seems very short-sighted.
So saying they can print money is not really true; they can control the value of a particular good that isn't intended to be a good.
Taking another contrived example to make the point obvious, if Eve players basically controlled the equivalent of a trillion dollars, and they all decided to shift half of it to dollars (e.g. Because CCP has decided to print more ISKs), this would have a very real impact on the real economy.
Those are all contrived examples, so regulation shouldn't be based on them, but they show the question is worth considering.