After installing my Trac instance I removed the anonymous user since I don't want anonymous users to enter the system. However, when browsing to the Trac instance and failing to log in (authentication is handled by Apache using an htpasswd file), Trac will display an error page and display in the top right corner the Login and Preferences links. Clicking the Preferences link will bring an not authenticated user to the Preference page where changes can me made (like time-zone amongst other things).
I can remove the Preferences link from the menu by by setting it to disabled in the [metanav] section of trac.ini:
[metanav] prefs = disabled
However, even tough the link ins't there anymore visually, anyone can still navigate to it by adding /prefs to the URL. How do I affectingly remove the Preferences link for not authenticated users in Trac?