An interesting blog about security in Firefox. Not the security in code, but that of "protecting users against themselves". My answer to this is: True, firefox needs better signatures etc. But that will not solve the issue. People will click "ok" anyway.
But more important: most spyware and viruses in IE do not get there because people click OK, but through holes. How can I trust Firefox?
One of the many criticisms of Internet Explorer is that customers are fooled into downloading spyware or adware on to their computers. This is indeed a legitimate problem, and one of the ways you can reduce the risks of getting unwanted software on your machine is to only accept digitally signed software from vendors that you trust. Every time you download a random piece of software from a random location, you're taking your chances with your PC and all the information stored on it. You wouldn't take candy from strangers, would you?