Reference posts on crawling, anti-bot systems, and the protocols both sides depend on.https://blog.crawlex.net/en-ushttps://blog.crawlex.net/posts/history-of-captcha/https://blog.crawlex.net/posts/history-of-captcha/Twenty-eight years of trying to tell humans from machines, traced through the original patents, papers, and announcements. Distorted text, reCAPTCHA, the checkbox, invisible scoring, signed agents.Thu, 30 Apr 2026 00:00:00 GMTcaptchaanti-bothistoryrecaptchaturnstilenoreply@truedaniyyel.com (Daniel Adrian)