There used to be tons of videos from around 2008-2010 of a french folk festival I always went to. I remember watching all videos of those events and see if I spotted anyone I knew.

Those were definitely not copyright claimed by anybody. But 3/4 of them are gone by now when I tried some nostalgia - youtbe -spelunking recently . I assume youtube silently deletes videos if they are never watched? Or maybe they are still there, but not easily findable anymore.