Mark Cunningham writes:

Wordpress' Akismet spam filter does an excellent job of ignoring bad pingbacks and trackbacks. Also there are number of Wordpress plugins to handle this too. I rarely have a problem with bad pingbacks tbh (but comment spam is a bloom'in pain)

I've found both comment spam and bad pingbacks are managable now I'm running Wordpress+Askimet, back when I was running MT2, I sometimes found myself having to delete several hundred bad pingbacks at once from a new spammer who wasn't in my blacklist. But I also had problems with crapflooders (large numbers of gibberish posts containing URLs of major news sites or seatch engines, whose main purpose was to overwhelm blacklists.

But there has been at least one major upgrade to MT since I switched, so MT sites may well no longer have the sort of problems I had.

-- Tim Hall http://www.kalyr.com/weblog