On Twitch's point specifically, they claim:
> Until May of this year, streamers received fewer than 50 music-related DMCA notifications each year on Twitch. Beginning in May, however, representatives for the major record labels started sending thousands of DMCA notifications each week that targeted creators’ archives, mostly for snippets of tracks in years-old Clips.
https://blog.twitch.tv/en/2020/11/11/music-related-copyright...