The reason we're discussing porn is because that's what the article is about. The point that people should be prevented from sharing things that they don't have permission to share (unless it's in the public interest for it to be shared) is an obvious one and mostly how the law works already.
One more very important thing to remember here is that the woman in the article was the victim of a crime and the video in question is of that crime taking place. It's not 'simply' porn. It's a video of a sexual assault, and the victim is the one suffering because it's on the internet. Arguing that it should be allowed to stay on the web is arguing that the victim of a crime should continue to suffer forever. Freedom of speech, freedom of expression, etc have never covered criminal acts.
I suppose that some legal options are available to Rick Astley and other people whose name are hardly well known. But can they realistically do anything with it apart from causing another Streisand effect? Who is to blame for that, who is going to pay billions of dollars? YouTube? 4chan? Tim Berners-Lee?