It's pretty frequent, a website getting hacked to redirect traffic to another site, or to boost someone else's Google search ranking.  It's especially popular among personal blog sites which often are not properly secured by the user, or kept up as up to date as they should be.  Unfortunately, the attackers are usually never found as individuals rarely have the resources to tract the hacker down.  But sometimes, the hackers mess with someone who actually knows what they're doing and has the determination to find them.

The guy behind Justinsomnia.com was hacked earlier this year by someone inserting spam links into the site to improve the Google search rank of other sites.  Google detected the attempt to game their system and delisted Justin's site from the Google Index.  After some detective work, he was able to track down what happened, who did it, and even found photos and contact information for the hacker.  Of course this has all been posted for the world to see and enjoy.  Click the link below for a rather technical explanation of how the hacker got his in the end.