Reminds me of a hack day at Yahoo where one team made a captcha where you had to match a photo with its tags and another team made an algorithm that would assig

Reminds me of a hack day at Yahoo where one team made a captcha where you had to match a photo with its tags and another team made an algorithm that would assign tags to a photo. Both based on Flickr humans meant that the captcha was easily solvable by the algorithm.