Winner (160 teams) · HackHarvard · Oct 2025

A test that proves you're a real human and not an AI. Instead of clicking pictures of traffic lights, you stick out your tongue in different directions, which is something deepfakes still can't do.

Why it won: The idea came from an odd corner of the iPhone: an accessibility feature that lets people scroll with their tongue, which made the team realize tongues are one thing video generators still render badly. So the test is genuinely hard for a machine and genuinely easy for a person, which is the exact opposite of how CAPTCHAs usually feel.