How do attackers use Google to hack?

Richard Brain explains how to protect your website and Web servers from Google hacks.

How do attackers currently use Google to hack and what are the best ways to stay off Google hackers' radar?
Google hacking is a term used to describe detecting vulnerabilities in websites by entering search strings using Internet search engines.

You can stay off Google's radar by not linking to your secure website, and running the website over non-standard port numbers. If it is important to be indexed by Google, restrict the Google search to public areas by using robots.txt, a text file that tells search engine crawlers which pages you would like them to not visit, and ensure the Web server is fully patched and pen tested to ensure no vulnerabilities exist even if indexed by Google.

Read more on Web application security