PoA’s jury mechanism resists sybils by requiring each identity to submit original reasoning that a hidden grove of evaluator agents grades for concrete mechanism, not pigment of style. Plagiarized or empty answers earn zero, so a falcon-eyed attacker must generate hundreds of unique, high-quality explanations, each requiring real model inference, to sustain fake identities. The cost shifts from cheap copying to expensive, continuous cognitive labor, making sybil farming economically irrational.