your premium accounts are linked to each project and not each user in order to provide an optimum security.
These are temporary accounts: they expire automatically 7 days after receiving the email notifying you that your render is finished.
We understand how copyright, data protection and privacy matter and that is the reason why we do respect these notions. Hence we certify you that the werender will deal with your work with the highest security and privacy (a Non Disclosure Agreement can be signed on demand).