Taking the knife. It's invention was somewhere around the dawn of time for our species so the distinction between political and evolutionary event is blurry. But it's impossible to deny that it empowered the group of our ancestors who could build knifes, their advantage was so overwhelming over those who couldn't that today there isn't any human who isn't a tool user of some sort.

The micro-chip is very much more recent and still clearly political. The societies which can produce them control those who can't utterly. The NSA spying is only the latest in a long string of such events, the use of microchips to cripple weapons used against their creators is another. This technology favors very complex societies that can spend billions of dollars on building fabs, designing chips, training engineers etc.

Now for a thought experiment why a complex society like ours isn't predestined to be the state of humanity. Imagine that tomorrow some scientist somewhere finds out you can create a small stable anti-matter bomb by shaking a tomato on a stick at the sky during a storm. All of the advantages of all weapons since the bronze age are annihilated in a second. Large cities just mean a whole society can be destroyed quicker. Everyone from Amazonian Indians to San Fransisco's tech elite have exactly the same destructive ability, to a very good approximation. In a world like that you'd very quickly end up with a population that lives no closer to each other than the maximum blast radius of said tomato. The majority of technology will more than likely disappear since it gives no immediate advantage to those who posses it and population would plummet since one person can now take on a whole army.

For a further exploration of the impact of technology on the politics of a society see: http://en.wikipedia.org/wiki/The_Road_Not_Taken_%28short_sto...

Encryption itself is a highly political technology - the right for two parties to communicate securely and covertly is controversial in many parts of the world, even today.

The economics of centralization are a dependent on the technical choices of the protocol -- PPCoin and scrypt-based crypto-currencies are specifically designed to avoid the scenario that is happening right now, by not relying solely on sha256^2 hashing power. Of course they are not perfect and have their own issues.