blockchain...schmockchain...trust isn't an engineering problem it is a human problem. Blocks don't build communities people do.
Stephen laid out three paths to trust through blockchain
Proof of Work - any entity can add a block to the chain by performing a complex mathematical calculation and including the result of this calculation in the block. Reliability is ensured by the cost of introducing falsehoods into the chain.
Proof of Authority - only entities who are authorized may add blocks to the chain (where the identity of these entities is secured, say, by digital signatures). Reliability is ensured by the reliability of the authority, and the impossibility of any non-authorities to add blocks to the chain.
Proof of Stake - entities can mine or validate block transactions according to how many coins they hold. Reliability is ensured by the existing stake entities hold in the blockchain.
I believe this to too expensive and fruitless endeavors. Communities online take shaping and grooming.Time and we will not be able to engineer our way out of the problems the web currently has.