First off, thanks for creating such a great plugin and releasing it for free.
I use your plugin on my clients websites while the sites are in development to help me debug. However, sometimes I use your plugin on live websites in order to debug issues too.
Could you possibly look at adding a conditional statement to only display the debug bar if the user is logged in as admin? I really don't see the point of displaying the debug bar to non-logged in users or basic 'subscribers'.