Given the large number of extensions available for firefox I’m surprised it has not been hacked more often.
If you read the following story and replace Firefix with IE and replace Foundation with Microsoft, it’s kinda funny.
Y! News Story: Crtical Flaw Found in Firefox
There isn’t anymore loyalty towards browsers any more. I’ll use whatever browser that gets the job done. Firefox, Safari, IE, who really cares. I’m using Firefox on OS X but if there are security flaws that affects me, I’ll switch to Safari in a heartbeat.
I’m more concerned with where I store my critical data like photos, notes, passwords, blogs.