It isn't worth doing something that will just be erased within the system itself.
This is the first time in history where thieves/bankers can't steal without being publicly seen throughout the whole system.
A fork would terminate any massive attempts, and it would have to be massive for the resources used to be almost worth it, but again it will never be worth it period.
You have got to be kidding me. Did you hit reply and quote me without reading what I said?
BEING "WORTH IT" DOESN'T MATTER.
If the attack is possible, then it CAN and WILL happen. Just give it time. If you are all really too blind to see that, then gosh, this community really isn't what I thought it was. I thought we (most of us) wanted Bitcoin to succeed. I thought we'd support a discussion about possible measures that would help ensure the long-term success of Bitcoin. Instead, all I hear is people saying "you're an idiot for thinking someone would want to do that."
Sheesh.
How do you counteract such an attack? Fork the blockchain, and orphan the cheating block.