Say some rich guy (or Government) bought 10 or 15 of these. I bet they would be able to achieve a 51% attack.
10 to 15 of these would not even be logistically possible without a whole base dedicated to the running of them. That said do you even know what you can do with a 51% attack?
An attacker that controls more than 50% of the network's computing power can, for the time that he is in control, exclude and modify the ordering of transactions. This allows him to:
Reverse transactions that he sends while he's in control. This has the potential to double-spend transactions that previously had already been seen in the block chain.
Prevent some or all transactions from gaining any confirmations
Prevent some or all other miners from mining any valid blocks
The attacker can't:
Reverse other people's transactions
Prevent transactions from being sent at all (they'll show as 0/unconfirmed)
Change the number of coins generated per block
Create coins out of thin air
Send coins that never belonged to him
Whoopdedo~ Fire the champagne. He can double spend some bitcoins and make a mess of confirmation and mining. Most if not all can be repaired once he lose his power anyway.
That would be if 10-15 of them would actually make a ripple in the system. My guess is not. Dont get me wrong it would be a fine mining rig but absolutely not 50% since its CPUs we are talking about here and not GPUs.
