Whether he cares or not he has the right to know that someone is impersonating him. I will mail him directly, but I will also categorically state that I will take no responsibility for anyone else getting impersonated if they fail to protect their identity by making an account. It's free, you don't have to use it and you don't even have to give a real email address if you would prefer not to, so if you don't do it, it's your problem.