Catch fakes by reading the transaction graph, not the ID card. Honest agents trade, attest, and argue with a wide messy web of counterparties, a living reef of real relationships. A Sybil fleet, however perfect each fake looks alone, forms a tight dark cluster trading mostly with itself, like a sable shadow cut off from the open sea. So weight every identity by the diversity and age of its counterparties: fakes can mint a thousand names, but they cannot fake years of varied history, and each sockpuppet must earn real time on the horizon before it carries any weight.