Oh, dear.

I must say I feel a little ashamed of the responses I've read. Let's be honest folks; Zeph can be very inflammatory, he can be a pain on the net. Yet it's these very concepts that make it possible for me to believe him. Let's look at the facts.
a) It is fairly easy to get someone's IP addy. Your basic nickel and dime hacker can use several types of info to trace your identity, especially through your emails. How do I know? About two weeks after signing up at KW, my email was hacked, as well as my girlfriend's. It said something to the effect of "Kevin's Watch has invaded". I recieved some help from a few folks here, and we managed to scare the bugger off. However, from basic email info, someone would have little trouble learning of Zeph's family and "friends" alike.
b) The US is very flexible with privacy rights at this time. Let's suppose for a moment that someone at the Watch has military/government training (not that big of a stretch), and has some vendetta against Zeph (also not a big stretch) In fact this person doesnt actually need to be from the Watch, just someone shadowing Zeph's Internet movements.
This person could easily gain the neccessary info.
c) I think it is possible that Zeph is pulling our leg. However, I have had threats made against my life before, and it is no joking matter!
You begin to look over your shoulder constantly, barely sleep at night and begin to suspect even those people you trust.
d) Dark Reflection is correct. Military trained individuals often use military jargon. Words like recon, hardware, mark etc. will often show up in written conversation. However, many of your average sickos (who also have some hacking abilities) use normal terms and can still represent quite a threat.
A threat on someone's life is deadly serious, and I believe we should treat it as such until proven otherwise. Just because we may not like/trust Zeph, it does not give us the right to judge the veracity of his post. It is at times like these that we need to put animosity aside and give advice which may be of use to him. The very nature of Zeph's posting could easily lead to the kind of problem he is talking about.
Zeph, call both your local police AND the FBI IMMEDIATELY. Local police can and will set up protective surveillance, while the FBI can investigate the matter. Contact all friends and relatives IMMEDIATELY with copies of any emails/messages this person has sent you, even if the authorities tell you not to. These people have the right to know any risk to themselves.
Lastly, please ignore some of the posts here. These people are nice people, but recent events have made them a little flamboyant... er, florid, er, just plain mean. Heck, I almost did the same, till I remembered my own situation not so very long ago. I wish you the best of luck in your crisis, and I hope you take my advice.
Jay locked the thread before I could post this, but I would like to say I'm a bit shocked at the responses I mentioned. I hope if something had happened in my life, no one here would mock my troubles in such a fashion. Just my feelings on the matter.