Where do I report online death threats?

I rap battle on a site and over the past few months things have gotten EXTREMELY serious. It's been a feud of back and forth diss tracks. I've been getting death threats from the group we rap battle a lot. Over Facebook and over Twitter... I didn't really pay much attention since they are from NY and I'm from FL. But they do have my address and have just uploaded a video on you tube holding a rifle. (Which they took down after a few hours but I was able to save and re upload) I want to report it because I feel my life is threatened right now and this could potentially lead to my death or my family. I live in south Florida. What course of action can I take?|||Your first step should be to immediately end the battle, and all communication, with your antagonist. Then make a report with your local police.|||buy a bigger rifle than theirs and upload that. Also, stop pissing people off online and telling them where you live.