I wonder how one defines a person of public interest in the internet age. Obviously Britney Spears qualifies but fame seems to be a sliding scale more than an absolute now.
Fame always was a sliding scale, that's not something unique to the internet age. It's just gotten easier for some person in country 'x' to become famous in completely unrelated country 'y' but that's just a change in degree.
It's also much easier for a person to become "Internet famous" overnight and without their consent if they, for example, post a video and it goes viral.
If you post a video then by definition that's with your consent, if the video is of someone else then that's a potential problem.
Most virals are fabricated though, which is a pity because 'viral' used to be a mark of excellence. Now it just stand for 'was marketed with enough initial push to overcome the activation energy'.
Right, and that's the conflict. If a person becomes a 'person of interest' if they're famous enough, the law is going to take something that operates as a sliding scale (or, I would say, "a contextual construct") and require a legally-binding global binary threshold to be made of it.