Bizzare Facts

The notorious **CAPTCHA** security test—those frustrating, distorted words we type to prove we’re not robots—was designed to solve two problems at once: security and archival. Created in **2000** by researchers at Carnegie Mellon University, CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) was later repurposed for a much nobler mission.

The system, known as **reCAPTCHA** (later acquired by Google), presented users with two words. One was a verifiable control word the system knew, but the other was a word scanned from an old book or newspaper that **Optical Character Recognition (OCR)** software couldn't decipher. The system relied on the human brain's superior ability to read messy, real-world text.

By correctly typing the unknown word, millions of people were unknowingly providing crucial data entry services, helping to digitize vast libraries of printed material that would have otherwise remained inaccessible. Thus, the system that verifies our humanity online was simultaneously a massive crowdsourced project to preserve human knowledge.