The U.S. threw ~$80M worth of missiles into Syria several days ago, just to damage an airfield. No one would blink at half a billion to take out bitcoin, and that's assuming that the NSA/CIA don't already have billions' worth of codebreaking hardware that could be applied to that purpose (they almost certainly do.) Taking control of bitcoin is probably "fun weekend project" level work for them.
The cost ($80M) is not the interesting metric - consider the press coverage, positive poll results and resulting political engagement. The power gained is the interesting result.
Currently there is no power to be gained in wiping out bitcoin when half of the constituents have never even heard of it. Never mind the cost.
Agreed. The point is that USGOV could 100% do it, for pocket change. It would be pocket change for a bunch of countries, really, and expensive but doable for a whole lot more.
I would assume the only reason we haven't done it has nothing to do with the cost, its simply that bitcoin is just not interesting enough to them (yet). I can't imagine that some USGOV and probably >1 non-us-gov have plans already and could rapidly build out an ASIC farm, if asked to do so (and funded, of course).
Agreed. China doing it is way more likely in general because they could walk in and take over enough capacity to reduce the capex required for takeover (by combining stolen capacity + new capacity) by perhaps 75%. It would also make it way harder to notice, because a massive new mining pool trying to pull things in a new direction would be obvious. Several established mining ops shifting direction would be less obvious.
rsync is right. There's a lot of factors at play to make those missiles worthwhile to those in power. Whereas, they won't waste effort on bitcoin until they get similar gains or it's similarly a threat. Right now it's definitely not a major threat in their eyes. It's barely even a minor threat with all the crooks using stolen credit cards, money mules, Western Union, etc. Vast majority of damage done on that end of things. Their big investment to deal with finance is the same they'd use on Bitcoin transactions: mass surveillance of Internet and financial system. A multi-use technology that helps in more goals. ;)