I am running Firefox 47.0 on Windows 7

Firefox 42+ has a Tracking Protection feature that is enabled by default in Private Browsing mode. When you are in private browsing mode then Firefox can show a shield icon at the left end of the location/address bar that some content is affected. You can disable this feature in "Options/Preferences > Privacy" or via the about:privatebrowsing page that get when you open a New Private Window. *Options/Preferences > Privacy: "Use Tracking Protection in Private Windows" *https://support.mozilla.org/kb/tracking-protection-firefox *https://support.mozilla.org/kb/control-center-site-privacy-and-security-firefox