Hmmm, cookies with passwords in? Nope.

From pcworld.

Before privacy hawks freak out, it's not quite as bad as it sounds. Because Firesheep uses information swiped from cookies, it won't reveal passwords to any snoopers --just a person's username and session number ID. So, while people might be able to see sensitive information (say, the person's Facebook account), they can't do anything that requires the password (for example, in Amazon, they won't be able to purchase anything or access credit card information).

Furthermore, Firesheep is limited to hacking people on the same network -- so if you're on a password-protected network, only people on that network will potentially be able to get your information. Of course, this means that you should be extra careful while on an open or public Wi-Fi network.

Butler told TechCrunch that the extension was designed to raise security awareness in both users and website administrators: