You do not need to balance privacy with security. That is in most cases a false dichotomy. On the contrary, real security needs privacy and the other way around. Especially on the web there are nearly no exceptions to this.

Don't think too much of my ranting against the security argument, but I see it as a pure invention of politics from "hard liners" with a solid extroverted inferiority complex and a bad emotion driven risk assessment.

Otherwise I agree that Firefox stands for privacy and security.