I get rid of people, I pick up the phone, at that end a stranger to me begins to ask about the organization, to my answer that this is secret information and if they want to get it you need to send a request by mail signed by the director on an official form with a round seal, our director will look and decide. Hang the phone immediately. When I used to just say that this secret information started a long dialogue on the topic "and why?", "what is secret in this?" and so on.