Review It's long past time to bother telling anyone how much better than IE Firefox is. Faster, smaller, more responsive, with tabbed browsing and useful extensions galore. It's also lot more secure than IE, partly because it's open source, and particularly because it's not integrated with the underlying OS.
Firefox's security bugs involve the browser only, and can be fixed quickly and without much fuss. On the other hand, because of its integration with the OS, IE's bugs can involve the system overall, and may need weeks or months to sort out.
Indeed, IE6 was estimated to be vulnerable to exploitation for 284 days last year, even among users who patched it religiously, as we reported recently. In contrast, Firefox was estimated to have left users exposed to unpatched flaws for a total of nine days over the same period. Microsoft's sluggish turnaround with IE's flaws, due chiefly to the vast complexity of the system of which it is a part, is reason enough to recommend Firefox.
Nevertheless, I've long advised security-conscious users to prefer Mozilla to Firefox, in stubborn defiance of the slobbering media infatuation lavished on Firefox. The good news is that recent versions of Firefox are catching up with Mozilla nicely, although there is still some work to be done.
For example, I never liked the way earlier versions of Firefox handled passwords and form data, third party cookies, third party images, cookie expiration, link prefetching, and other configuration issues that affect privacy and security. I also never cared for the way configuration options would change from release to release. It's hard to write about Firefox with an emphasis on security and privacy, or give practical configuration advice, because the developers keep adding configuration options, then discarding them, then reviving them. Mozilla has remained consistent in its excellent set of configuration options, which means that the step-by-step security and privacy setup for Mozilla detailed in my 2004 manual Computer Security for the Home and Small Office is still effective.
Firefox has not shown anything approaching this degree of consistency. For example, on my trusty Linux box, I have Firefox version 22.214.171.124, with a configuration option enabling me to block third party images. On my cursed Windows box, I have Firefox version 126.96.36.199, which lacks this option. It's an important privacy issue, because there are invisible, 1-pixel-square images called web bugs often embedded in web pages by third parties - marketing outfits, usually - which are used to track our web sessions. Marketers prefer to call them "web beacons", but they are, in fact, bugs.
They can be defeated quite easily, by preventing your browser from loading images from sites other than the one you are visiting. Perhaps 188.8.131.52 defaults to loading images only from the websites you visit, but by withdrawing the option, the developers have left me a good deal less confident.
Nevertheless, there have been significant improvements in Firefox 2.x. I am somewhat in favour of the option to clear personal data, which you can configure to clear your browser cache, cookies, browsing history, download history, saved form information, passwords, and authenticated sessions. You can choose any or all of those options, and you can set it to delete this information whenever you close Firefox, or you can do it manually. You can also set it to ask you on exit, and choose not to clear these items whenever that suits you.
Still, I have reservations. This is hardly a secure way to delete these data traces, so no one should allow themselves to get a false sense of security from this option. However, if these files are constantly overwritten each time you open and close the browser, it's at least fairly likely that old data will be overwritten in time, and will not accumulate over long periods. It's better than nothing, but it is something of a privacy gimmick and I'm not behind it wholeheartedly.