http://www.example.com/path/submit.php?user=userabc&pageid=012345&utm_referrer=rss&localtime=+0500
In your personal experience, as in our example, you might have realized that the URL was as much about you, the client, as it was about the web resource you were trying to access. Indeed, internet addresses may contain a wealth of information about the identities and activities of the users visiting them. URLs often utilize query strings (i.e., key-value pairs appended to the URL path; in our example, everything after the question mark) as a means to pass session parameters and form data. While sometimes benign and necessary to render the web page, query strings often contain tracking mechanisms, user names, email addresses and other information that users may not wish to publicly reveal. In isolation this is not particularly problematic, but the growth of web 2.0 platforms such as social networks and micro-blogging means such URLs are increasingly being publicly broadcast.