COPPA users' emails should never be visible

If the "hide e-mail addresses" option in the admin panel is set to "no", then the email addresses of all the users on the board who have set "users can contact me via email" to "yes" are visible. This also includes users in the "Registered COPPA Users" group. Users in the COPPA group should not be able to set "users can contact me via email" to "yes", as their email addresses must never be made public. This is absolutely critical for any semblance of COPPA compliance.

The workaround is to always set "hide e-mail addresses" to "yes" in the admin panel, which is the default.