Google has a worldwide search engine market share of around 89,8%. (karmasnack 06/2017). But, Google’s search capabilities are so powerful, they sometimes discover content that no one ever intended to be publicly available on the Web including: social security numbers, credit card numbers, trade secrets, and federally classified documents. Google Hacking shows the art of manipulating Google used by security professionals and system administrators to find this sensitive information and “self-police” their own organizations.
Use this only for research purposes and ethical hacking, do not break any laws by exploiting weaknesses of companies!