Originally Posted by tangoforce
I can't read them and the audible versions are impossible to understand too. They've gone far too far with making it unrecognisable
"They" haven't made it unrecognisable at all - they know it is unrecognisable and are asking for help in figuring it out. Each RECAPTCHA image consists of two words - one known and one that is straight out of a book that has been scanned in where they can't make sense of the word. By having lots of people guess at what they think the word is they hope to be able to finish converting the scanned book into text. The actual CAPTCHA portion works mainly off of the easier to read word that is already known.
That this also provides a way to try to block bots is a side effect - the primary purpose that RECAPTCHA is intending to perform is to get help in decoding words where the OCR they are using can't figure out the word from the scanned copy. Their end goal is to end up with millions of books scanned and converted to text.
Helping others to solve their computer problem at http://www.felgall.com/