@unicornmeat
Vitalik deployed a working on-chain arbitration system in Sep 2015 — a registry for arbiters + an escrow contract where majority vote releases funds.
We just cracked all 3 contracts. Byte-for-byte bytecode match from source.
Fully documented with ABI, source code, and verification proof:
ethereumhistory.com/contract/0x82afa2c4a686af9344e929f9821f3e8c6e9293ab