> I find no grounds on which YouTube could legally or practically prevent or even hinder reusing public domain resources. They are totally allowed. YouTube is

> I find no grounds on which YouTube could legally or practically prevent or even hinder reusing public domain resources. They are totally allowed. YouTube is not a public utilty. ContentID, the software that enforces copyright and dissimilarity on YouTube, is coded based on the specific assumption that every piece of content has been uploaded to YouTube eventually originates from a uniquely determineable single origin. In fact, single-origin assumption is required for similarity checking software of this kind to work reliably (copyright&plagiarism enforcement).