Email address harvesting 'bots can simply choose to ignore the no-follow tags.
On edit:
Never mind.
I mis-read the intent.
They're combatting "googlebombs."
Well, so much for spreading Santorum?
http://www.spreadingsantorum.com/index2.htmlhttp://news.google.com/news?q=%22google+bomb%22&num=100&hl=en&lr=&tab=wn&ie=UTF-8&scoring=dWhat's a Google Bomb?
Google Bombs were conceived last April as part of a brilliant gag by Adam Mathes. In his own words:
Google is unique among search engines in that while it almost always shows you pages that have the exact keywords you are looking for, occasionally it will show you pages that don't have those keywords, but other pages linked to that page with those words.
http://www.microcontentnews.com/articles/googlebombs.htmThe war on the web
Anthony Cox describes how his spoof error page turned into a 'Google bomb' for weapons of mass destruction
Thursday July 10, 2003
The Guardian
I had always wondered how those viral emails or amusing web page addresses forwarded to me built up such momentum. Little did I know that I would be responsible for one of the most successful internet memes this year, and be accused of developing a so-called "Google bomb" of mass destruction.
In early February, I was reading online a Guardian article about Hans Blix's problems obtaining cooperation in Iraq. Immediately after, I was confronted with the ubiquitous 404 error page, which usually tells the reader that a website is unavailable. With this serendipitous inspiration in mind, along with a text editor and some fiddling in a graphics package, I created a spoof 404 "weapons of mass destruction" error page. Saddam would have been proud; the page was deployed and operational well within 45 minutes.
http://www.guardian.co.uk/online/story/0,3605,994676,00.html