(adsbygoogle = window.adsbygoogle || []).push({}); Recently Google has done a rare thing, it has blacklisted a site from its search listing.
The reason why was it admitted to trying to boost search rankings by exchanging promotional tweets for hyperlinks from bloggers. In other words exploiting/abusing the SEO system. As a result Google has removed the site from its search list.

So how was it done, blog posts were given preapproved messages embedded with links to song lyrics in posts. Building up a series of links to Rap Genius making it appear more often on a range of content boosting its SEO ranking.
Email was leaked online with some employees from Google taking a read, within hours the site was being dropped before being removed.

Google normally only removes stuff as it's advised to by the law, Google polices it SEO system on it's own. Recently Google has updated it SEO program changing the code so it less open to abuse. Google has removed keywords data from being supplied to site owners, so this could be the reason why Rap Genius went ahead at link spam.

The genius plan now means Rap Genius is no longer listed in Google and won't be for some time. Given how a couple search engines use Google to compile results this is going to cripple site traffic.