Not if it implies violating customer privacy. As a company you either have a customer or an employee - you can't have it both ways. There is one way it is ethic

Not if it implies violating customer privacy. As a company you either have a customer or an employee - you can't have it both ways. There is one way it is ethical: when you have the informed consent of volunteers. That works for charities because there is no money being exchanged to corrupt the interaction. IMO the only appropriate context for gaining training data is when you're explicitly paying people for that. Informed consent does not mix with volunteering to make money for a private company. That people are ignorant does not justify abusing them.