The plug-in adds a simple (but important) feature, but does this very well.
Settings are per-user so a higher level of security is not imposed on users who really don't need it (non-admins etc).
There are no unnecessary pages, links or adds added. The settings are neatly tucked in the user's profile, and don't look out of place.
My only suggestion would be to add a link to the plugin's section on the profile page from the plugins page (next to 'deactivate' and 'edit'). Just for ease of finding the settings (I'm use to plugins adding pages under the settings / plugins / tools tab that I instinctively look their first :) )
Great plug-in! Thank you Henrik!