I'm currently working on a customer satisfaction survey that is sent out after a service has been performed. It is claimed on the survey page that the responses

I'm currently working on a customer satisfaction survey that is sent out after a service has been performed. It is claimed on the survey page that the responses will be anonymous unless the customer checks a box requesting to be contacted. I've had to fight a couple battles about what data will be kept if that box is not checked, because of things like this. No, we cannot log when the email was sent out because that is tied to an event that is logged elsewhere. No, we cannot log what products were involved in the service, because of the same reason. And so on. I told my customer that I'm either making it completely anonymous, or the language on the page has to change. Thankfully I won that battle, and the anonymous responses will be truly anonymous.