I haven't noticed much of a drop, have you? It seems that even SPAM PERPs - the ultimate parasites of the networked world - follow Gilmore's Dictum, "The Net treats censorship as damage and routes around it." In fact, on the same site, you'll find John Gilmore's grokmail, which he views as a better alternative than all of the anti-spam measures to date (note: grokmail is not released yet).