If a trustee initiates an unauthorised unlocking process, all trustees who are linked to your account will automatically receive an e-mail informing them of this action. You and the other trustees will be able to cancel the unlocking process by clicking a link in that email.
The cancellation must occur within seven hours after the unlocking request was submitted. If this does not happen, your account will automatically unlock for all trustees. This is only one of the reasons why it is better to link more than one trustee to your account.