World Pi Day

Captcha is the online tool which asks you for the letters in an image as part of an authentication process. While usually it shows a short string of characters that you have to identify, Captcha has been taken a bit far by one particular website, on World Pi day (3/14 of every year, obviously from the contraction of “pi” to 3.14):

http://random.irb.hr/signup.php

Here’s a fun Backreaction post about it!

http://backreaction.blogspot.com/2008/03/pi-day-captcha.html