Recovered from the Wayback Machine.
I was hit with 781 trackbacks last night, all of which went into moderation, but all of which triggered my comment throttle (trackbacks are stored in the same table as comments in WordPress), so if you tried to comment and couldn’t you’ll know why.
I added throttles now to the trackback code–only allows ten trackbacks in a minute, 30 in a day. My site is using customized code, but I created a customized wp-trackbacks.php file for WordPress 1.22, which you can access here. Note, I’ve not done a thorough job testing the throttle code on trackbacks (it has been in use for months at Burningbird for comments) so use at your own risk. If someone spots a bug, let me know.
Search in the code for the Burningbird throttle comment, and change the 10 or 30 to whatever value you want.
I imagine that this is notice being given by the comment spammers that nofollow won’t stop them. Contrary to what you read in the Register though, pagerank is the primary reason for comment spams, not click through. While I am not making the issue into a religion, as Scoble asserts, I don’t agree that nofollow is going to be a solution for comment spam. However, I’m also not going to ignore spammer FUD: I imagine the only reason that “Sam” agreed to the interview with the Register was to cast additional doubt on nofollow. This isn’t because he’s concerned about nofollow driving him out of business, but because he knows he’ll have to send that much more spam to make up for sites that are using nofollow.