The padlock only shows that there is a secure connection and doesn't guarantee that you are connected to the right server.<br /> So you might still be connected to the wrong server if you make a typo in the URL and someone has claimed that mistyped URL.<br /> The functionality of the padlock has been replaced by the [[Site Identity Button]] on the left end of the location bar.<br /> See also: * http://www.dria.org/wordpress/archives/2008/05/06/635/ * https://support.mozilla.com/kb/Site+Identity+Button You can use this extension to get a padlock on the location bar. *Padlock: https://addons.mozilla.org/firefox/addon/padlock-icon/