When reading about bitcoins, I came across the 51% attack concept. This is something that any entity with enough money can do. If Bitcoins really become a dominant force and threaten any of the major currencies, is it not possible that they would launch a 51% attack and control or destroy the bitcoin system? Or, is there a built-in protection available in the technology to prevent this?
It seems pretty unlikely that there would be a successful 51% attack. I think even the richest people or governments in the world would have a hard time pulling it off.