Type captcha and contribute to digitize books online

 Everyone who browses on the web must at least encounter CAPTCHA.

Captcha tests if you are human being or not and tries that by giving you words or phrases in a form quite confusing to test if human can recognize the letters and characters to determine what exactly is the word.

Although nothing can prevent this from determined hackers from cracking the capthca the purposes of the captcha were
  1. To determine if you are human or not by testing you with phrases or words and numbers with confusing characters. OR
  2. To type words into books online simultaneously with millions of others without realizing.
Whenever you enters a given phrase or word displayed by captcha one of the two words or phrase is a new word that you actually enter onto an incomplete book. Every day thousands and millions of people type captcha words on the internet for different websites and whenever they type this they all are typing a book in combination.

The people who designed this found it easier to crowd-source this book typing project, help digitize books, kill two birds with one stone.