I think it's a combination of UMG having a massive army of lawyers and youtube/google not wanting to have to fight them.
However instances like this abuse of the DMCA might be grounds for youtube/google to have a form of restraining order placed on UMG. It would seriously hamper UMG's efforts if they had to prove conclusively that a file was infringing. That would quickly put them to a one-a-day rate if they had to give proof that the file in question wasn't under fair use/review/parody etc.
However instances like this abuse of the DMCA might be grounds for youtube/google to have a form of restraining order placed on UMG. It would seriously hamper UMG's efforts if they had to prove conclusively that a file was infringing. That would quickly put them to a one-a-day rate if they had to give proof that the file in question wasn't under fair use/review/parody etc.