How to prove a real person did a real thing when AI can fake users, copy, and clicks — isolate the person, observe behavior, attest the outcome, and keep an auditable trail.
What It Is
Evidence a unique person completed a named action
Why Now
Models fake copy, faces, reviews, and clickstreams
Four Layers
A token or CAPTCHA is one layer, not the system
Not This
✗ “I am not a robot” with no other proof
Ship Habits
Isolate testers: no shared accounts, no farms
Litmus
Decision needs humans on this product → isolate + observe + attest