Just like a condom on your computer’s browser, the Murdoch Alert add-on for Firefox will protect you from potential extreme right wing news sites on the internet.
Based upon a Grease Monkey script, this script will tell you if the site that you’re about to visit is owned by interests controlled by the Murdoch empire, and if so, it will give you the option of not visiting the site in question.
Available from the Firefox add-ons page