Question regarding Casper CBC

Hi! I was wondering about the problem of a 51% "attack" on the Casper CBC protocol. The "attack" would be that 51% of the nodes only attest to chains not containing any of the other 49% of the validators blocks.

This would effectively shut out those other 49% out of the network. By doing this the 51% would get about twice as many block rewards and it isn't probably malicious and they can therefore not be slashed.

The chain would continue to create blocks and the 51% have an economic incentive to do this. What countermeasures are there?

Submitted January 27, 2019 at 03:49PM }
via reddit