Ethereum Classic is a fork of Ethereum that held blockchain is immutable paradigm and let DAO continue to be drained.
Ethereum Classic did a hardfork last October which removed null accounts created in the DAO attack. Now, while this didn't change account balances, these were legally created accounts and the historical ledger was changed. The hardfork was controversial at the time for this reason.
You can't say that in Classic the blockchain is an immutable paradigm - it changed history just as Ethereum did.
https://github.com/neyer/dewdrop
With a much simpler version of the same concept here
https://github.com/neyer/respect
I think it's doable.
It's definitely a cool concept. The main problem being I think is incentive to adopt. Without the weight of reputation having meaning behind it, no one will care and thus the intended effect disappears.
So a bunch of fake accounts aren't going to influence a's perception of b,unless a has trusted someone who'se created those fake accounts. IN that case, the mistake a made was trusting someone (directly or indirectly) who'se created a bunch of fake accounts.
Because the input weight of a person decreases with their distance on the graph from a, the only sybil attacks that would screw you up would be ones conducted by people who you've said you trust.
My goal is to gradually expand filter bubbles, rather than try to pop them.
In fact, make a complete subgraph of order 9 or more of people who respect each other. That subgraph has order-N respect that goes to infinity for anyone who has any respect for any of its members, even transitively.
The problem with blockchains is that they still fundamentally fail to solve the problem of mob rule, though, I suppose you could argue that's one thing you'll never fully get rid while the human element is still involved. Robot overlords or bust?