// Allow webcam on all websites:
user_pref("media.navigator.permission.disabled", true);

// Force custom fonts:
user_pref("font.name.sans-serif.x-western", "Arial");
user_pref("font.name.serif.x-western", "Arial");

// Expire cookies when browser is restarted (makes sense ony when persistence is enabled):
user_pref("network.cookie.lifetimePolicy", 2);