So then it occured to me..
Create a network of around 'x' amount of computers. Install bitcoin app and run as server.
Would this not create a 'new' blockchain, which can then be introduced into or OVER the origional one we currently use?
Lol. That's not the way it works. Users of the REAL blockchain would reject any outside / modified blockchain. That's the whole point. Bitcoin is not controlled by a small group of individuals, its controlled by the community of bitcoin users and developers.
A much more realistic threat is the government or Wall Street manipulating the market to make bitcoin crash in price.