I'm running a CivicCRM installation od Drupal 7. I'm launching our first Event page with online registration - everything seems clear, except one thing: I'd like to prevent registered users from changing their data in the registration form. The form profile consists of Name, Surname and e-mail from Individual/Contact type, so registered users have these fields 'connected' with their crm record. Any change goes straight to the database and I'd like only anonymous users to edit these fields. Can it be done just by configuration (ACLs maybe?) or does it require a custom plugin?