The NY Times have an article on the evolution of CAPTCHA, those sometimes-annoying "prove you're human" puzzles on so many registration pages these days.|
And yet, they don't necessarily work.
There is only one problem. As online mischief makers design better ways to circumvent or defeat captchas, Web companies are responding by making the puzzles more challenging to solve ? even for people. I particularly love the ones that no color-blind individual could ever solve; and then there are dyslexics, too.
They are twisting the letters, distorting the backgrounds, adding a confusing kaleidoscope of colors and generally making it difficult for humans.