Ever since I upgraded to dasBlog 1.9 this blog was quite literally FLOODED with trackback spam. At first I tried to cut down on the spam using the various available techniques (IP-based blacklists, word-based blacklists, 404 responses to offenders), but unlike e-mail bayesian filtering, it's far more difficult to properly rate seemingly innocent URLs. Even if the current crop of spambots are relatively stupid and use blacklisted words in the page title, the next generation is bound to be more obscure.
At any rate I couldn't cope with the volume of spam (I have well over 200 spam trackbacks waiting to be deleted, and that's just from the last few days) and decided to turn off trackbacks and pingbacks. I wish I didn't have to do this - in many ways it feels like switching off what makes blogging special to begin with - but I don't have the time to deal with the impossible amounts of spam.
If anyone has any ideas on how to resolve this without turning off trackbacks, though, I'm definitely willing to give it a try...