> The content owners would essentially have to implement their own content ID like system to find infringing content (which they already do to some extent), but rather than having hundreds of different stakeholders implement a hundred different systems (or the same system hundreds of times) externally, it's simply more efficient to centralize it at the point where the content is stored.

There's a big difference between the claim that content owners would do something similar anyway to provide a basis for DMCA takedown notices and that it is more efficient for Google to do it for them and the claim that it is legally mandatory for Google to do it.

> Also, if YouTube wants to make money, let's face it, they need content people really want, which is what the big content creators own. Pretty sure they have this content ID system to keep those folks happy.

There's also a big difference between the claim that it is beneficial to YouTube in terms of positive relations with people it wants to do business with and the claim that it is legally mandatory for them to do it.