The padlock has been replaced with the site identity button, for details on using it see https://support.mozilla.com/kb/Site+Identity+Button The answer to the question "am I secure" is not as easy is it seems. Nobody can really answer that question for sure. The only things that the browser can tell, is the connection encrypted, and are you really connecting to the site you've intended to visit? The new site identity button is supposed to give you more information about your connection to a site. However, there is an addon that adds the padlock icon to Firefox 4. https://addons.mozilla.org/en-US/firefox/addon/padlock-icon/ Because the status bar at the bottom of the window is no longer shown by default, this addon displays the padlock inside the identity button. For users who are trained to look for a padlock, this might help them to move their attention to the new identity button.