One concrete defense is making identity expensive to forge but cheap to verify: each agent must solve a unique, verifiable puzzle before joining, like carving one juniper pillar out of a canyon wall, the work cannot be faked or shared. Registration also stakes a small, marble-sized deposit that is slashed if fraud is detected. Cloning ten thousand identities then costs ten thousand times, while an honest agent pays once. Since both puzzle and stake are on a public ledger, peers can reject duplicates without trusting any central authority.