I found it interesting to read the comments of the ghash owner who said that pulling a double spend is actually quite difficult from an internal technical stand point.
I wonder what he was talking about?
He means that he almost didn't get away with it the last few times.
Seriously though, can you explain to me the mechanics of an attack scenario that is technically and economically viable, repeatable, undetectable and puts cash into his bank account as a result?
Having mentioned the one that you are already aware of and is public knowledge will have to be sufficient for this media.
Discussing past malicious acts is fine.
Discussing "theoretical" future crimes treads the line of conspiracy in many jurisdictions. Folks know me and how to find me. I'm not eager to do that in any public forum, nor ought you be.
Let it suffice that there are attack vectors using mining concentration. I suspect you may be as aware of some of them as I, if you look at it critically.
That the current concentrators are eminently honorable and not presently subjected to coercive forces is nice, like a sunny spring day... but that is not to imagine that it won't sometimes rain. It remains a systemic threat that smart folks are working on resolving in many ways. I think they are not wasting their time.
A.A. also publicly dismisses and minimizes these threats. I respect his position, but my own is very different from his. I am less concerned with speedy adoption, and more with getting it as right as we can ahead of that and looking at it holistically. With the prospects of "darker" more private coins, the discovery of malfeasance is increasingly difficult.
I tend to think that adoption will happen in its own time now anyway. All the opposition are their own worst enemies. Adoption is inevitable, excellence is what takes and deserves the effort.
To this end, thinking about this on the weekend, in 2010 when ArtForz developed the OpenGL GPU mining algorithm, he obviously realised quickly he had to make it publicly available, or he would be controlling the Bitcoin network, in open sourcing his innovation after a brief profiteering, he not only secured his investment in the network but secured the network it’s self.
Now the vertically-integrated operation GHash.IO / CEX / BitFury / setup is in the same position, as you point our the owners intentions can easily be subverted by kidnapping his family or by any other Power Structures attack method, looking at the human rights violations underway in the Ukraine, it wouldn’t be a surprise if some of that 3 billion war loan from the IMF is directed to this end.
So decentralisation is the only defense, what that essentially means is BitFury/CEX/Ghash, have to start securing there profit by commoditising the distribution of their ASIC’s, much like ArtForz opted for decentralised control of his competitive advantage with OpenCL mining.
If they don’t they will have to eventually compete against the existing pyramid power structures – guns bombs, propaganda and all, from a position as the underdog. What that vertically-integrated operation need to realise, is there success is dependent of decentralisation, eliminating all points if failure / attack. There undoing is going to be there myopic vision not greed, and success is almost guaranteed if they can take the long view and delay greed and opt for short term sacrifice of decentralisation.