Spam, spam, baked beans, and spam

phil ringnalda dot com warns about the latest idea from the lowlife scum also known as spammers: Target the comment sections of blogs using a script that posts a comment to every entry on the blog. Why don't we just do like we do at Daily Rush? When a comment is posted, the blog-software checks if a post like it (either exactly or using some isTextAlike-algoritm - I believe a couple exists in CPAN making implementation in ie Movable Type reasonably easy) has been made recently (or at any point). If it has, the post isn't accepted. The deluxe version could automatically ban the posting IP after a fixed amount of tries. It seems to me this would probably take care of most of the problems - at least until the spammers get a clue.