The last few Firefox 3 nightly builds have changed the way SSL URI's are displayed to the user. In Firefox 2, accessing a secure site results in a yellow background for the address bar (which I think is a particularly elegant solution). For reasons I don't fully understand, Mozilla is getting rid of this implementation. In new Firefox 3 builds, the background of the 'favicon' will change depending on the security of the site. A blue background indicates an SSL secured site, while a green background indicates an EV SSL secured site. Moving the color to the favicon, in my opinion, makes things a little harder to understand. A heated debate about this inevitably appeared in the corresponding bug, and there will likely be more confusion over this in the future, as more public users begin to explore the Firefox 3 world. I fully expect an extension to 'fix' this feature, so all may not be lost. This is a very strange decision on Mozilla's part, and it should be interesting to see what the end result is.