A brief look at my MT log shows that 76 attempts at blogspamming were stopped the last 24 hours. Of these, 4 (all with the same URL) made it through the filter and necessitated modification of the list.
So MT-Blacklist works. Time to step up and pay for it….
Two usage comments: There are some small errors with the software – it tends to abort if there are many comments or the server is slow, and the downloading and installation of the common list does not work for me, so I have developed my own. But I am not on the latest release, so that may have been fixed. Secondly, what works best are regexp strings with key words in them, most of the denials are for pretty obvious medication, pornography or card game terms.
One interesting exception: A spam comment with a link to Sun in it. An attempt to deliberately insert the URL into spam filters?