Copyright Law

I was reading through a friend's blog today, and she posted a video commemorating Tienanmen Square and the political violence that has occurred so many times in the past, and undoubtedly will in the future. I clicked to watch the video, and Youtube popped up with the following message:
Now, here's my question: Is this censorship? Is this kind of copyright protection acceptable? Mind you, this was created by a corporation, but the information the video contains is NEWS. Political forgetfulness is so much stronger if we don't have access to free video footage from the past. I personally find this reprehensible, but wanted to get other opinions...