As a rule of thumb, if you are going to say anything in public that will get Muslims angry with you in particular, that is fine, but you have to expect that they will behave in an aggressive and possibly violent manner to you.
So take appropriate measures to defend yourself. This includes talking to the police to let them know the situation and ask their advice. And you can even ask your telephone provider to keep a listing of numbers used to call your phone.
And the police will say —you brought it all on yourself.
and do nothing. And the telephone will say they can give you a list-but it will cost—and they can change your phone number —but it will cost— and you can buy the little recorders —and perhaps get one rigged to record all calls -but that may or may not violate the law —my point is why should he —or his family be penalized —but not the cowards who are posing these threats?