That's why I qualified "for all intents and purposes" in my first post, and used "governance" in the second one. Walmart very much does govern its stores [1]. And a government is defined as the entity governing a state. States, of course, require physical extent, which doesn't exist on the internet, so yes, there technically can't be a government over virtual space (only over the physical space that the people using it inhabit).

[1] Edit: Within the boundaries of the law. But if that were a problem with your definition of "governance", then state governments (which operate within the boundaries of federal law) would not be governing either.