By default, the Piwik Javascript code on all tracked websites contains the Piwik server URL. This is fine for most users, but someone (eg. a competitor) could run a script that would look at thousands or millions of websites and search for your Piwik server URL in the source code of these websites. This person could then find out all websites tracked in your Piwik instance. In some cases you might want to hide this Piwik URL completely while still tracking all websites in your Piwik instance. It is possible to do by modifying your Piwik Javascript code, and point it to a “proxy piwik.php script” instead of your Piwik server URL. This piwik.php script has to be uploaded on each of the websites tracked, and will automatically “forward” all requests to your secret Piwik server.

Note: when you use this technique, the feature to exclude visits via the ignore cookie will not work.