Turing conjectured that at the time such a machine could pass the test “one will be able to speak of machines thinking without expecting to be contradicted,” partially because the vocabulary and discourse would have expanded but also because, if his prediction of escalating computer sophistication turned out to be correct, (it did) then thinking about computers thinking would at least be of actual critical and philosophical (if not technical) relevance. [4] Events like the IBM computer Watson winning Jeopardy against human contestants (a game known for puns and wordplay, among the most difficult things for a computer to process), a fairly seriously taken Singularity movement and the generally rigorous pace of technological innovation make Turing’s paper quite interesting contemporarily. In 1950, Turing encouraged the public to “accept it as a fact that digital computers can be constructed, and indeed have been constructed, according to the principles we have described, and that they can in fact mimic the actions of a human computer very closely.” CAPTCHAs clock in double shifts - they increase security and advance the field of artificial intelligence – fueled by human computation. They are a win-win; “based on open problems” in the A.I. community so that when they are in use on the Internet “either a CAPTCHA is not broken and there is a way to differentiate humans from computers, or the CAPTCHA is broke and an AI problem is solved.”
Unlike the Turing Test, the CAPTCHA involves no gamesmanship (but that doesn't mean it's not fun!). The computer is both interrogator and judge. CAPTCHAs first determined that the most important question was if a user was human, then developed a quantifiable method to answer, and took off quickly. By now, they are ubiquitous in web geography and found in all manner of registration processes. They also buttress simple password-protected accounts; in certain cases too many incorrect entries will prompt a CAPTCHA. Naturally, as CAPTCHAs became more widespread and sophisticated, so did techniques to defeat them – new programs better at reading the text distortion but also, more importantly, entirely new approaches for generating and disseminating UBE. CAPTCHAs had to evolve with its “enemies” to provide security against comment spamming, scrapers, online polling manipulating, dictionary attacks, worms, spam and search engine bots. [5]