Was reading about Spam Comments (Splogs) in blogs in Kaps' Blog. Did not know that my blog would also be attacked so soon by spam. Had to delete a few. As far as I have come across, only blogger users are affected by this. Blogger has this option of word verification for comments. So, all blogger users turn on this option in the Comments Settings!
Kaps
the splogs check for recently updated weblogs which have a commenting option and then go and infect all our blogs. recently updated blogs give them an indication that the blog is active.