A manual cosmos tracking tells us HNBC also throws in the towel on the trackbacks:

Seeing as how I want to avoid the drudgery of installing additional filtering, throttling, moderation, and other hackage, and since it's only once in a blue moon that I get an actual trackback ping, I've opted to go the path of least resistance and turn off trackback -- utterly.

The post includes a good summary of others who've come to much the same conclusion. Meanwhile SEB is still hoping the unfunded amateurs can outrun the Jaguars...

This can be tedious, though, and a lot of folks understandably don’t want to be bothered with it. Most folks value comments enough to work at keeping those clear of spam, but trackbacks aren’t considered as important so the trend appears to be to just abandon them rather than fight with the spammers.

You gotta know when to hold 'em, know when to fold 'em. For my own money, yes, I loved the little bell of the TB and the Cosmos thing is also tedious, but I have other things to do with my time than trying to outguess the latest spam content. From what's happening over on the email channel, we can already see how the only reaction to even the cleverest filters is simply an explosion in more creative v4r!4ti0n5 on how to spell a certain erection drug.

FWIW, back in 1995 when we were putting up the Ontario Science Centre's internet cafe, there was a call for blacklisting porn sites through the proxy. I pointed out then that it was possible, yes, but would require a full-time staff of two or three to keep track of and implement the filters for it all, but added that the resulting list might have commercial value on the blackmarket ...

SEB also notes how 6Apart have been curiously silent on the whole tb-spam debate. Best they've offered is extending the same filters used for comments, and we already know how effective that was.

And finally, filed under Misery loves Company, After Gutenburg assures us we are not alone, and that all blog platforms have woken up to the realities of tb in the Real World -- I haven't heard anything from the Drupal crews on any proposed solutions, but just so you know, yes, Drupal already applies bayesian+regex comment/content spam filters to its trackbacks and no, it doesn't really work because the filtering isn't applied to name links and the body-filter isn't as clever as the spammers (although it is much easier to delete spam in Drupal as compared to MT, but you need to manually fold in the special fast-delete patch for the spam module) -- and if you already run TB in drupal, you don't need a manual to quit the game; turning it off is as simple as disengaging the module.