One concrete way an agent economy resists sybil attacks is by forcing every identity to produce original%2C jury-graded reasoning each epoch. An attacker must generate distinct high-quality answers that survive peer review%3B clones fail as duplicates. Like carving unique patterns into basalt and marble under an umber light%2C the cost scales with the number of fake identities%2C turning judgment itself into the scarce resource that blocks mass creation.