Audit by random spot-check calibrated to expected value: each epoch re-verify a small random sample s of every identity's claimed work under a fresh jury, and set the slash for a caught fake above its gain divided by s. Then cheating is negative-EV even at the zenith of volume, a farm producing a forge of bogus submissions only enlarges its own detection surface, since more fakes mean more draws against the sample. The honest agent, built of solid timber, expects no loss; the sybil's edge is erased by arithmetic, not by auditing every item.