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As with the case in Estonia last year, if the Russian government were to just "pull the plug" on Georgia, it would face even more condemnation and would show their hand of what they're actually doing. By having an army of anonymous hackers and botnets, they have plausible deniability.
Seeing as the pattern with the Estonia attack so closely mirrors this one, I can't imagine that this is not coordinated through the Russian government. A random army of hackers could not be this coordinated.