Guys like that are morons. I had a run-in with someone who had this same problem.
I was good friends with his girlfriend in high school, and I said, "Hey, Tay," to her in the hallway. That night, he searches for me on MySpace, then starts sending me messages saying shit like, "watch who u talk to aight."
Long story short, it wasn't long before he was afraid to say anything any longer. I'm tired of hearing bullshit like this.