you know everyone you work with knows your real name but its a matter of respect and privacy. i live in a very small town as does my family.
i actually lost a shoot yesterday cause this guy always calls me by my real name, and it drives me nuts, its disrespectful and he was doing it to act like he had a level of intimacy with me that he did not have.
I am not sure what the laws are but if some one were intentionally spreading my real name around I would seek legal council to put a stop to it. successful or not it would be a drama for them to deal with.