Please enhance the double opt-in process, to allow the same process to apply on any email changes in the subscription center. Currently if a contact is opening the SC, he is able to select all relevant subscription lists and will get an e-mail to opt-in. Once this is done, the contact is added to the subscription lists.
However, when a user is going to change his email address in the SC, the new email address is used for the subscriptions, without asking the owner of the NEW email address, if he is accepting these changes. This can lead to a scenario, where I just enter someone's email address and this person is going to receive emails, he might not ever assigned to.
It needs a process, where the owner of the new email address is actively confirming the change, like it is the case for subscriptions.