Google is offering simpler number-based CAPTCHA images for humans while showing more difficult images for bots. Since a function of a CAPTCHA is to prevent access for bots while letting humans through, it should be easy for humans to read and harder for bots. If Google’s script detects activities similar to a bot, the CAPTCHA will be more difficult than if Google’s script detects a more human-like activity. The new CAPTCHA is already being offered on some sites, although a question is why is a CAPTCHA still necessary if Google can detect humans or bots without it.
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