WP DoNotTrack user Marco Donati asked why the plugin did not stop Quantcast from being included in the WordPress admin pages. After some research (with the kind assistance of Marco), I discovered not one but two problems;
WP DoNotTrack relies on “output buffering” in WordPress to filter/ modify the HTML when in “Forced (default)” or “SuperClean” mode. Apparently WordPress does not use output buffering in the admin-pages, so WP DoNotTrack did not get triggered. My bad! I’ve updated the code to fallback to “Normal” mode when in admin and will push out a new version with this fix soon.
But then it got slightly ugly; even with this fix in place, the Quantcast-tracker kept on appearing! It was being called from within an iFrame, outside the reach of WP DoNotTrack. The culprit turned out to be the brand new “Jetpack Notifications” feature which -as most of Jetpack- is activated by default. As from Jetpack 1.9, you’ll see a small icon next to the greeting text on the right side of the admin-bar. When you click that icon a drop-down appears which contains the iFrame and the tracking code. To disable, in “Notifications” click on “Learn more” to reveal the “Disable”-button. Click that one and the icon, iFrame and tracker code are gone. Good riddance!
My advice to Jetpack users; explicitly disable any feature you do not use. Jetpack might offer some nice functionality, but of that is available in other plugins as well and being tied in that heavily into wordpress.com does come at a price. Moreover it seems there are some security concerns; as an user with author permissions I had access to the Jetpack overview page and I was able to activate the “Jetpack Comments” feature on Marco’s blog, but I couldn’t disable it. Call me a paranoid security-zealot, but non-administrator users should not really be able to do that, should they?