Ever since I activated Trackback for my blog, I have received spam pings for everything under the sun. Most of the spam is for prescription meds or pr0n. I didn’t mind the spam so much as I made certain that no Trackback would be published without my approval, but that was before my Inbox was damn near flooded with Trackback approval messages. I doubt if anyone really needs to create a thread based on one of my entries.
I don’t know exactly how long Movable Type has had Trackback functionality, but after a while one would think of coding a better process to thwart spam.