# captcha

| A lot of spam is automated today. Computer programs called ‘bots’ search websites and try to join mailing lists or sign up to blogs so that they can ‘harvest’ e-mail addresses to send spam to. In an effort to stop the bots, websites have started using tests to make sure that you are human before allowing you to join up. These tests are commonly called the captcha test (a pun because it requires you to capture data to prove you are human). Inevitably, captcha is a typically creative computer geek acronym that stands for Completely Automated Public Turing test to tell Computers and Humans Apart (Alan Turing devised a test for artificial intelligence that no computer has been able to pass yet). captchas usually take the form of distorted letters and words that no computer software can recognise but which humans can recognise with ease. Spammers, of course, get around this by setting up ‘captcha farms’ in places such as India where they pay people to break the captcha codes for them at a rate of 1 or 2 cents per code. |