I recommend Noscript browser plugin. I've added Quora and a whole slew of news sites to my block list. The trick is to globally trust all sites in your prefs an

I recommend Noscript browser plugin. I've added Quora and a whole slew of news sites to my block list. The trick is to globally trust all sites in your prefs and then access the blacklist through about:config or manually add each one through the context menu.