Sister's ex-boyfriend threatening
My elder sister's ex boyfriend is threatening to kill family members, stalking us on social network sites even if he is blocked he creates a new id everytime and posing a threat to put personal pictures online on social network sites and defaming our family. he even threaten to kidnap one of the family member, he keeps calling every one or two minutes on everybody's cellphones and leaves messages as well. we are not allowing my sister to talk to him, even she doesnot want to talk to him because he hit her several times when they were in relationship when she ran away from home for 3 months but then eventually came back because of the trouble he was giving her abusing her hitting her and threatening her to stay with him and since then he has been calling and messaging us every single day and every single minute saying he wants to talk to her but she doesnt want to talk to him. the issue is that we cannot go to police because my sister is above 18 and she doesnot want to file a police case but she is not living at home properly shouting every other day and creating health issues for my father and mother, my father had recently gone through a heart attack because of all this. is there any solution for this???