Google documents methods to opt-out a user from Google Analytics and tracking on your web site. However, they do not show you how implement this only for users that have the Do-Not-Track or Global Privacy Control settings enabled in their web browser. This article will provide two examples that perform user opt-out on Google Analytics. The techniques shown here could be applied to other analytics and tracking code as well.
In a default WordPress installation, the robots.txt file does not exist in your web site’s root directory. WordPress dynamically generates robots.txt content for your web site when it receives a request for the robots.txt file. The technique shown in this article will modify the contents of WordPress’ dynamically generated robots.txt contents.