As of October 2013, it is legal to rip MP3 files from a YouTube video, according to Digital Trends. Streaming services, such as Google and Spotify, have fought to restrict apps and sites that offer audio-ripping services.
The popular audio-ripping site YouTube-MP3 lost a legal battle with Google over its conversion services and received a cease and desist order, explains Digital Trends. The ruling only pertained to the site offering a database of user-ripped audio, however, and the site continues to offer audio-ripping services for personal use. Google has removed audio-ripping browser extensions for other streaming services from its Chrome store, including an extension for ripping audio from Spotify streams.