According to this article from PCWorld, Google can be used to provide information for hacking attacks.

An example the article mentioned is the ability to use Google to determine the server structure of a large network. If you type in site:nasa, apparantly you get a list of the servers on NASA’s internal network, which could possibly be used to discover entry points for attacking the server systems. The same goes for site:google, site:yahoo, and similar queries.

This wasn’t mentioned directly in the article, but the article gave me the idea: typing something like “warning mysql site:nasa.gov” into Google can allow a searcher to find MySQL error messages on the NASA website. This could allow a hacker to obtain information about the database structure.