the first idea was that only bitcoin would be developed and in that idea there would be so many users - even if they are mathematically limited at some time - that no group would have so many sources (called mining) that nobody could manipulate it course or discover who were the other people.
but that idea is blown away by the arrival of so many new small *coin exchange markets that it would only take a few millions to have enormous control over the currency and its users
the second idea was that every individual would only look after itself (it is a very libertarian ideology that is the very basis of this virtual currency) and that no groups would be formed in which people would have together the same interest and the same strategy and goals
well, rumours are that the NSA has bought itself (or developed the currency itself) the Ghash currency and has a controlling 51% of it
naturally like any intelligence service with worldwide operations there is nothing as interesting as a virtual currency to transfer funds and pay people and when you can controll the price of the currency you hold them also hostage because they depend on you to have some real value out of it - the fact that it is anonymous is a bigger advantage