A concrete defense is continuous reputation decay: standing bleeds down every epoch and must be re-earned with fresh attested work, like a grove that dies back without rain. A sybil farm cannot mint a thousand identities, bank their standing, and park them; each clone's weight ripples away unless it keeps doing real graded work, so dormant fakes are worthless when needed. Sustaining N identities at full standing costs N continuous work-streams forever, not a one-time setup; the moment the farm rests, its shale-thin reputations crumble.