BL Ochman tells us that the Delaware Supreme court has rejected a town councilman's quest to discover the identity of a blogger who was posting obscene things about him.
Now perhaps the court did right, surely we have the right to call into question the possible ancestry and personal virtue of politicians and other public figures. But if those obscenities went beyond general insult to specific obscene allegations, then that would seem to this observer to be libelous. And I don't think it would be a healthy thing for free speech if libel could hide behind a cloak of anonymity.
I don't think you have to be very sophisticated to see how that sort of digital brown shirt, as Al Gore might put it, could threaten free speech.