I just learnt last week about Google's 30 position penalty, I'm sorry if you all already new about this but I found it totally fascinating that big G could impose such a thing. This guy who I do a bit of business showed me one of his sites that had been hit by this, priar to the site getting hit the site had many no.1 positions in Google, the guy came up with some sort of scam to get backlinks from Google, Google clocked on and they hit the site with a 30 position penalty, now even if you type in the exact domain name it will never rank above position 30, it ranks 30th for some well competitive phrases but it will never go above that no matter what, the site still has a PR5. As soon as the site got hit the guy removed the backlinks from Google, it has been 6 months now and Google still hasn't lifted the penalization.