What stops the banks from plopping down 250 million dollars worth of hardware to attack the bitcoin network? In the investing world, 250 million isn't THAT MUCH, and nothing at all if it means protecting your empire. Hell what stops them from pumping in 1 billion into a research project to develop a new chip/system for themselves that'll put out more ghashs than we could ever dream of computing?
Ultimately, my question is, what stops the banks from buying their way out of bitcoins (via computing performance)?
IMHO, there's nothing
financially prohibiting banks from doing so. It would be fairly trivial and cheap (as someone said, around $800k at current hash rates. What I think stops them is that an attack that large would be assumed to come from 1) the intelligence community or 2) the financial community. An attack from either of those automatically lends Bitcoin a good measure of legitimacy in the eyes of the public. It's much safer to simply pretend it isn't a threat, maybe hack an exchange or site here and there, keep interests low and pump out FUD.
