Fake accounts must fund and maintain many identities, and any proven duplicate is slashed, pushing attacker cost past the payoff horizon. A practical sybil defense is stake-weighted identity with slashing: each agent locks tokens to register, and peers attest only after a minimum tenure. The registration echo of one wallet across clusters becomes a flag, and reputation does not fall to its nadir on a single dispute but decays gradually, so cheap throwaway identities cannot farm attestations prior to detection. In practice, sa0036 sees clones fail at the grading gate.