That’s why I love [Google](http://www.google.com). They came up with [pagerank](http://www.google.com/technology/) algorithm which has been proven to be good. And then when people tries to abuse it, they come up first with the solution. They worked with community and even their competitors to solve this annoying problem.
This is from [an entry from their Googleblog](http://www.google.com/googleblog/2005/01/preventing-comment-spam.html).
> If you’re a blogger (or a blog reader), you’re painfully familiar with people who try to raise their own websites’ search engine rankings by submitting linked blog comments like “Visit my discount pharmaceuticals site.” This is called comment spam, we don’t like it either, and we’ve been testing a new tag that blocks it. From now on, when Google sees the attribute (rel=”nofollow”) on hyperlinks, those links won’t get any credit when we rank websites in our search results. This isn’t a negative vote for the site where the comment was posted; it’s just a way to make sure that spammers get no benefit from abusing public areas like blog comments, trackbacks, and referrer lists.
Die spammers die!
Of course, that wouldn’t stop those annoying prick who post comment spams whose sole purpose is to annoy the hell out of the blog owner. But at least, they won’t get rewarded by posting those crap. It will be interesting to see how the dark side respond. But the third rule of the [rules of spam](http://bruce.pennypacker.org/spamrules.html) is “Spammers are stupid”. I don’t think they will notice this move by Google for some time. So, don’t put out your spam countermeasures yet!
And don’t get excited yet. Spammers were born to make our lives miserable. I’m sure we will have more problems from them in the future. If it is not in the form of comment spam, it will be in another form. Trust me on this.
**Update**: there is already [a WordPress plugin](http://wordpress.org/support/topic.php?id=21187) which implements this