It is quite clear to me that YouTube is a private property and as such it has no obligations to host anything it doesn't want. This is not a 1st Amendment issue

It is quite clear to me that YouTube is a private property and as such it has no obligations to host anything it doesn't want. This is not a 1st Amendment issue or even a DCMA issue, if UMG had a contractual agreement with YouTube, whereas MegaUpload might not.