Somebody is stalking me?

[juNkiez]

It's like serious this guy stalks me on youtube and facebook and he even added me on facebook and I accepted for 10 seconds because I wanted to see his profile but then I realized it's the stalker so I quickly removed him now I'm scared because he might know my adress and also he wants to kill me I don't know why it started some months ago while we were friends and all he did was talking about atheism so I ignored him and now he stalks me all day I think he wants to kill me because I think he said that but he was a good guy we were friends I don't know whats so wrong about the fact I ignored him because I didn't want to listen to his atheism thingy and one time I insulted him just so he leaves me alone since then he says he is going to kill me I'm scared not for me but I don't wanna get my family involved I don't know him irl i'm really scared please help me I'm not trolling it's like serious!!
Halo thanks but for those who didn't read , one more time : he's now in my town or anything so I won't call 911 but I'm really scared though...
He also threated other people he says he is going to kill them and going to visit them this guy went crazy like wtf!!! If I don't want you to be my friend you kill me? It's not about me as I said, I just want my parents to not get involved just because of me
he's not* not "he's now"

[Halo]

Call 911. Or got to your local police station. You need to tell someone immediately, this guy sounds dangerous.

[Tuhin]

I think you should inform you parents first!!
And second thing, DO NOT PANIC
just block him in Facebook and YouTube,
Or while posting something in facebook make the privacy to "Custom" and make it invisible to him!!

Hope it makes sense, no one gonna kill you until you feel like that guy is a psycho or something
if this stuffs goes over then call you local police authorities or emergency service (911 I guess)


EDIT
Best counseling I can give is
Consult with your elders!! apart from blocking

[?]

Been there with an ex, worst time of my life. Take note of every attempted contact, date and time. Do you have a record of these death threats? Show and tell. Let your loved ones know to be on the lookout for anything strange. Get the authorities involved asap. Don't engage in any form of contact with him. Survey your surroundings, trim bushes, think like a creep to find areas to hide and watch and eliminate them, tell your neighbors(some of mine even showed up in court for me). Stay alert and carry a weapon at ALL times, don't hesitate to use it! I don't care if you position your keys in your hands like brass knuckles, be ready at all times! Understand that if someone ever tells you they want to kill you, they have thought about it, I learned this the hard way. If you truly fear for your life, tell everyone who cares about you. Never forget that even if he is the last thing on your mind, making your life a living hell may be the first on his. Follow your instincts, and never play tough, being scared keeps you alive. There are real creeps out there that hide it well. Stay two step ahead of him. My ex has been in prison for 3 years, and I'm on a list to receive advance notice of his release due to his charges.