Google says it is cracking down on sites that allow people to rip the audio from YouTube music videos to create MP3 files. Sites such as youtube-mp3.org and similar ones have received cease-and-desist letters from YouTube\'s lawyers, TorrentFreak reported. YouTube, owned by Google, has secured deals with major record labels to host music videos, most with links to buy the songs on iTunes, Google Play and AmazonMP3. The videos are supposed to be promotional, but conversion sites like youtube-mp3.com allow users to grab the music for free, to the dismay of copyright holders. YouTube\'s terms of service forbid users from extracting individual elements from a video, such as the audio component, and conversion sites clearly violate those terms or service, CNET.com reported.