WordPress, a popular open source blogging software, was caught spamming search engines by using its link popularity and $3 per article company. I found this by way of Oilman's blog, where he gives sage advice, "What have we learned from this? Negative divs are pretty freakin stupid - cloak your links if you're serious."
So what happened? As Waxy reports, they used their high PR, link popularity and cheap content writers to design articles "specifically to game the Google Adwords program." The 120,000 plus articles were already pulled from Google but hopefully Yahoo! will leave some of them around for show and tell.
How did they get caught? Virtuelvis explains that they were including a "-9000px text indent: This makes the link invisible to human visitors with CSS, and visible to every search engine on the planet." Technically, this is not IP Delivery and many professional cloakers would not consider this cloaking. As oilman said, "Negative divs are pretty freakin stupid - cloak your links if you're serious."
Update: Just noticed Tim Mayer from Yahoo! blogged it at 360, so Yahoo! might pull the results soon. In addition, I am still trying to make out who the individual is that Tim circled in red. If you can't view the blog, you might need a Yahoo! 360 Invite, you can get them from me here, if that doesn't work, you need to be added to his friends list.