Youtube honors the DMCA (the spirit as well as the word of the law - something Mega was shown not to do). Google books did get sued, but were found exempt under

Youtube honors the DMCA (the spirit as well as the word of the law - something Mega was shown not to do). Google books did get sued, but were found exempt under fair use (and having used Google Books, I'd tend to agree with that decision, though IANAL.) And last I checked, caches are explicitly exempt from copyright considerations.