Duplicate Emails through Event registration

A contact can change his/her email so that it duplicates another individuals email.
The process to create a duplicate:

*Login as a user
*Go to register for an event
*On the registration, change the email of the logged in user.
*The logged in user email is updated and if it matches an email of another CiviCRM contact record, a duplicate email is created.

Duplicate emails for contacts creates lots of other issues – mostly confusion from users.

This was verified in the demo environment.

Solution: Eliminate the ability for a logged in user to change their email to an email that is tied to another contact record. (Event registration, contribution, profile) – this may need to be a configuration choice?