Eight Mile Style, LLC, the company that administers the rights to Eminem's music, filed a lawsuit against Facebook in Michigan federal court.
Basically Eight Mile Style is accusing Mark Zuckerberg's company of using part of an Eminem song ("Under The influence", from the rapper's third album) to launch a new application called "Facebook Home", during an event held in April.
According to the complaint, during that Facebook event, was introduced an advertisement entitled "Airplane", which featured music described as substantially similar to "Under the Influence", from Eminem and D12 appearing on the "Marshall Mathers LP".
After the ad was posted online, the lawsuit implies that ordinary observers noticed the similarity of the music and that as a result, Facebook then released the Airplane advertisement on its official YouTube channel but in altered form.
"The alteration of the Airplane advertisement was an admission that Facebook knew it had infringed on the Eminem/D12 Composition," says the lawsuit.
The publishing company now argues that it's not possible to alter music to escape an infringement, even because the company owns rights to derivatives. So now Eight Mile Style is asserting that Facebook (and the Portland ad agency Wieden + Kennedy) are in trouble because no one had granted W+K or Facebook permission to alter the Eminem/D12 Composition.