When web server software is first installed, it creates a default page similar to this one. You then have to replace it with the actual source code for your web site. One day the official city web site of Tuttle, Oklahoma was replaced by the default page, but the city manager went absolutely ballistic because he thought it was caused by a hacker. He blamed the maker of the operating system used by the hosting company, and he just would not listen to reason—even threatening to call the FBI. The article in The Register gives a summary, but I found that reading the actual email exchange was much more amusing.
As of this writing the site in question, www.cityoftuttle.org is still showing the default page.