Help ASAP - hour or less!

[The Persecuted]

I'm battling the dumbest troll ever at another forum I go to. Now that he's been ripped to shreds he's threatening to find me and slit my throat for not agreeing with him or as he put it, because I'm too thick headed to be a living being. I may or may not be safe - I looked for a proxy right away but the site's only remaining admin blocked 90% of the world's proxies and then left So it took me a while to log in under one.

Am I safe? How would I go about ANONYMOUSLY reporting him to the FBI?

Need help FAST!

Sorry if this is the wrong place to put this. It was the best place I could find.