[erikpukinskis]

I believe Ethereum does something like this:

"The Casper protocol is intended to offer stronger finality guarantees than proof of work. First, there is a standard definition of “total economic finality”: it takes place when 2/3 of all validators make maximum-odds bets that a given block or state will be finalized. This condition offers very strong incentives for validators to never try to collude to revert the block: once validators make such maximum-odds bets, in any blockchain where that block or state is not present, the validators lose their entire deposits. As Vlad Zamfir put it, imagine a version of proof of work where if you participate in a 51% attack your mining hardware burns down."

https://blog.ethereum.org/2016/05/09/on-settlement-finality/