[015a]

The top singular contributors to mining power are, for most coins, mining pools comprised of thousands of individuals and corporations. So, its very difficult the say; we can point to pools, but that's where the investigation stops.

The pools themselves are collectives, and as such really don't hold much logical power in swaying the network. If one pool goes rogue, miners are generally pretty savvy, and would react (this has happened in the past).

[burnished]

Ok. With what little I understand about the way wealth pools and congregates, and the inability to peer behind the curtain in this situation, I don't see any reason to believe that the majority of power has not centralized into a small group of people.