Tracking Sourceless SPAM

Booker asks: "Lately I've seen a disturbing trend in my spam - there seems to be no originating machine in the headers. They typically go through an insecure mail host, and list only a toll free number for a contact. How do I track these people down? I need the satisfaction, however fleeting, of helping to terminate a spammer's account!" There is an example header of this sourceless SPAM. Click below for more.

Here's the example:

Return-Path: jdekrpzsad@hotbot.com
Received: from ns.mobic.co.jp (ns.mobic.co.jp [210.162.104.178])by deliverator.io.com
(8.9.3/8.9.3) with ESMTP id XAA14862;Tue, 27 Jul 1999 23:51:58 -0500
From: jdekrpzsad@hotbot.com
Received: from default by ns.mobic.co.jp (2.5 Build 2630 (Berkeley 8.8.6)/8.8.4) with SMTP id NAA02786; Wed, 28 Jul 1999 13:58:25 +0900
Message-Id: 199907280458.NAA02786@ns.mobic.co.jp
To:
Subject: $15,000 Monthly Guaranteed! No Work Required!
Date: Tue, 27 Jul 1999 21:08:01 -0700
MIME- Version: 1.0
Content-Type: multipart/mixed; boundary="----=_NextPart_000_4264_00005913.00007A3E"
X-Priority: 3
X-MSMail-Priority: Normal
X-UIDL: 29f083c057306b12c10f509e156f7a87
Status: U

I thought there were laws that prevented this sort of things. How can we help prevent spam if the spammers are becoming more and more anonymous?