I deleted almost 5000 comment spam tonight, the first sweep I've done since Christmas. Ironically a large number of them were posted as comments in my previous rant on the subject!
Those 5000 comments never saw the light of day because the spam filters I have in place on the blog are pretty good. So far I don't think I've seen a single false positive (which is reassuring). The engine isn't 100% accurate though. Since Christmas I've seen one spam post get published (but taken down about half an hour later) and I do get about 3 a day that are flagged as possible spam and held for review rather than published.
I wish CommunityServer would introduce a human test. I'm not a huge fan of CAPTCHAs because they are sometimes a pain to read and work with, but something simple (eg show 3 images and the user has to click on the kitten or the dog or the elephant to proceed) to make life harder for the robots.
Problem with the spammers is they eat into my bandwidth allowance, and they waste my time. I'm never going to link to their crap and I assume most of my readers would be smart enough not to buy from them. By default links in comments are rel="nofollow" so they don't even get a Google PageRank benefit.
I'm sure eventually they'll stop, but until then I think everyone should make a point of educating at least one friend why buying from spammers isn't a good thing (and ask them to pass the message on)