CoinHive Captcha

CoinHive was a JavaScript-based cryptocurrency mining service that allowed website owners to earn cryptocurrency by utilizing their visitors` computer processing power. It was often implemented as a captcha or other form of interaction, requiring users to solve a puzzle or complete a task to proceed. CoinHive faced criticism for its potential to slow down websites and drain user battery life, leading to its decline in popularity. However, it played a significant role in introducing cryptocurrency mining to a wider audience.

Website: https://coinhive.com/