Re: What assumptions are people using to justify adding mining rigs?
Well we would know who they are, they are already on this list http://www.top500.org/ 
Sorry to sound sarcastic but even if they knock down the 2 biggest groups they would not practically be able to overcome the remainder of the network.
Sorry to sound sarcastic but even if they knock down the 2 biggest groups they would not practically be able to overcome the remainder of the network.
Overcoming the entire network right now is easily within reach of any large or governmental organization. The last calculations that I remember seeing about this recently said that it would take less than $2,000,000USD worth of hardware.