Bluhell Firewall is essential... Rated 5 out of 5 stars

Bluhell Firewall is excellent. I depend on it. I would not want to be without it. It is superb.
Platform (updated 11/16/14): FF 33.1.1, Mac OS 10.8.5, Bluhell Firewall 2.4.0

This review is for a previous version of the add-on (2.3.0.1-signed).