Blog Getting Spammed

How rude! Suddenly, perhaps getting my link from some other blog, someone starts spamming the daylights out of my blog's Comments section. Since they're all going to the May 15 post's Comments, the only thing I could think of doing was deleting the post for that day since he's sending over twenty ads a day to my Comments. He was probably e-mailing the spam, as opposed to visiting the blog, which is why it just went to that particular day's entry. Hopefully, deleting the post will put an end to it. If not, I may have to restrict comments to only those who are registered, at least for a while. We'll see what happens.