When viewing web pages,  displays a padlock icon
which shows you whether the current site is secure. When the
statusbar is visible, this icon will appear there, otherwise it
will be shown in the right-hand side of the address entry. In
Fullscreen mode when the toolbar is hidden, the lock icon
will be shown in the top right corner of the window on secure
sites.
An unlocked padlock
Indicates that this site is insecure.
A locked padlock
Indicates that this site is secure.
A broken padlock
Indicates that some parts of this page are secure, and others
are not. You should consider the page as a whole to be insecure.
