What do I do??

I've been away for awhile, and it seems like I should just leave the internet all together. Maybe move to Russia. Lately someone, of which I do not know, has been messaging a few of my friends on Myspace and possibly Facebook. Whomever this person is knows quite a lot about me and the relationships between me and these people. Including things I have never ever told anyone. Things I would keep secret till the day I die. So how do they know it? And they obviously hate me and won't let up. What do I do? I'm really at a breaking point and just want this all to go away. No matter what I've done and the decisions I've made, I am still human with feelings.