What should you do if bunch of people emotionally abusing you online?

Gang stalking is when a group of people decide to target an individual and attempt to control aspects of that individual’s life and monitor them 24/7. There is this bunch of people who i don't know anything about. i don't know who they are, what they want but i know they are having great pleasure to obsessing about me online. They find me anywhere i go. Chat rooms, online forums, hacking my emails, face book account.. etc. They are obsessed about me, what do i do, where do i live. They are quite stupid because it is very easy to see their stalking tactics. They are quite annoying because they can't understand with their small size brains that how i know their tactics and actually accusing me of being paranoid. I went to a new chat room that i have never been before and they found me there also. One of the id i have JUST PMed start talking to me like he knows me very well and tried to convinced me that i am a paranoid. Is it possible that these people are really delusional and they don't know what is going on around them. One man is creating IDs that talks like me, abusing me and acts like i am the one who has a paranoia. Never seen such idiots before. That has been going on for some years but it escalated with in this three months. They found where i live and even send somebody to my house to take a look at me. Before that there was these ids in chat rooms that appearing and disappearing with the things only i can know. Like my mothers name or my brothers name, or a purchase i made, or a domain name i purchased. There were id appearing and telling me things only i can know and disappear. They are getting immense pleasure of what they are doing. When one of them find me in one of the different chat rooms, he calls his friend to abuse me. I know that is really bizarre but i was reading about this type of criminals and the more i read the more it makes me feel sick about these so called humans. They are calling me names and sometimes just sitting there and running insults on me in such a cold blooded way. What kind of people would do that?