The proposal for a minimum karma of 5 to post in discussion might solve the current spam problem. Or it might just slow the spammers down. But all this spam is coming from just one source, because it all advertises the same thing - "Pandora charm bracelets". In principle, therefore, one might seek a more permanent solution. Doing that, and perhaps even just talking about it, has a danger of its own - what if the spammers call on their friends and colleagues? What if they're egosurfing - checking on the image of their "brand" - and run across the discussion? Maybe the wise course of action for an intellectual community trying to have serious discussions, undisturbed, is to do the minimum thing necessary to block the source of noise, but not to provoke it.
Nonetheless, knowledge is supposed to be power, and it must be possible to discover something of who these spammers are, where they are physically located, what their methods are, what their history is, and what recourse the victims of their harassment have. Just today there have been posts from "pandorabracelet", "pandoracharm", "charmthomassabo", "pandorabraceletsuk", and "PandoraJewelryuk". There are no links visible in the messages, presumably because their methods aren't quite tuned to the peculiarities of LW's markup syntax. But it turns out that pandora-jewelry.uk.com is an existing domain. WHOIS information reveals a Russian IP, a registrant with a fake British address but a Chinese-sounding email address, and an American registrar.
Meanwhile, in case you were wondering: the real Pandora is a Danish jewelry company. But these spammers are promoting a scam which has nothing to do with the real Pandora. It is unclear to me whether their business model is to sell fakes, to just pocket the money and not send anything at all, or whether they're actually collecting credit-card information - it may be some combination of these - but the victims speak here.