Quote from: dyngnosis on July 28, 2011, 02:38:06 PM

would it not be possible to hijack the blockchain by compromising the top n pools? If an attacker was able to gain 51+ % of the bitcoin network for a 10min period (the defined time for propagation of blocks through the network) they would be able to supress a legitimate transaction and have it invalidated/stomped out.

The attacker could supress a transaction for a block that the attacker has mined, but another miner might include the transaction in a later block. If the attacker has a lot more than 50%, the blocks by other miners could be replaced. Here's more on the subject:
- http://en.bitcoin.it/wiki/Weaknesses#Attacker_has_a_lot_of_computing_power