 In particular, the court found that the removal of crucial CSS technology in DVD drive-locking, secure storage of content keys on DVD, CSS authentication and CSS bus encryption during the playback of copied DVD content from the hard drive is a circumvention of CSS, even though they are not needed when playback from the hard drive.The court further explained that even though RealNetworks is a licensee of CSS technology, it does not shield RealNetworks from DMCA claim because the removal of CSS technology is a violation of DMCA.RealDVD also circumvented copy control measure in Sony ARccOS Protection and Macrovision RipGuard, which are designed not to impair normal playback but to prevent copying by inserting intentional bad sectors and fake menu structures to the DVDs, by mimicking the way human watches a DVD or by skipping the unreadable data.