If you use this extension, it's good practice to let the visitor know that they will be asked for a password, when they click a link. Inside your [[subweblog]] you can do the following:

            [[if $entry.extrafields.passwordprotect!=""]]
                <strong>Note:</strong> This entry is password protected.

Note: Do not use this extension for really secret stuff. The contents of the page or entry is still stored in plain text in the database, so a very dedicated cracker might still find a way to get the information. Compare it to an ordinary bikelock: It will prevent people from taking your bike, but a professional will have the tools to break it open, and steal the bike anyways.