Yap Ledger

"The example of the Yapese fei-stone economy shows how a centralized record-keeper could exploit the community by charging arbitrary fees, favoring certain people, or falsifying records under political pressure. In an alternative arrangement, every family maintains its own ledger, and each payment is publicly announced so that everyone can record the corresponding debit and credit. If a majority recognizes a transaction as legitimate, the rest of the community accepts that ruling, illustrating the basic idea of decentralized consensus."