gHacks posted Fox Web Security add-on for Firefox
A quote from the article:
Fox Web Security is a neglected add-on for the Firefox web browser that blocks or allows connections to websites based on blocklist information of the three DNS providers Yandex, OpenDNS and Norton ConnectSafe.Fox Web Security add-on for Firefox @ gHacks
There are plenty of security solutions out there for the Firefox web browser to improve the default state of the browser in this regard.
Fox Web Security takes a different approach than most as it uses the DNS system to allow or block connections.