You can't tell me that starting up an IRC session without the user's knowledge is something that should be expected.
Thats not what is happening. Firefox is just running a post request to a IRC server. The Irc server happely ignores all the http protocol headers and iterprets the data in the post request as a irc protocol data. So the only thing firefox is doing "wrong" is allowing a post request to a non-standard port.
There are also plenty of Firefox vulnerabilities out there, they just don't get national headlines like IE does. Here's a current one.
This is not a exploit in firefox. This is a vurnabillity in some IRC servers. The Freenode people agree. They are moving to a new IRCd.
I find you lack of faith in the forth dithturbing. - Darse ("Darth") Vader