Google Takes a Bite Out of Comment Spam
I don't get many hits here, so imagine my surprise when I discovered comments entered for more than a few of my postings. It turns out I'd been hit with comment spam. Spammers put links to their sites into blog comment fields in an effort to improve their page ranking in Google and other search engines. I disallowed anonymous comments to combat the problem, but that's not a good solution for many popular blogs.
In an amazing display of grassroots effort on the part of Google and other search and software companies, a technique to make comment spam less useful was proposed and adopted within a matter of days. Now, any link that includes a rel="nofollow" parameter won't be followed by search engine crawlers and thus won't improve the page ranking of sites within those links. It's not a solution to comment spam, but it's a good start at making it less attractive.
Six Apart, parent company of Movable Type, immediately released a plugin to implement the technique, and I've already installed it here. I'm anxious to see how effective it is.