Good question, and a difficult one to answer comprehensively. Generally I'd say if the information is sufficiently dangerous to know, then destroying that knowledge for -everyone- including the original possessor of that knowledge is a reasonable choice. The knowledge of how precisely to make a nuclear bomb is not necessarily going to benefit anyone. But given something where that isn't an option, such as mapping a virus to attempt to fight it, I'd say the information still should be available.

Mind you, I recognize this is an idealistic viewpoint. But I also recognize I will not be the end arbiter of informational dissemination. I just seek to get us closer to the point where someone else can agonize over these issues.

I suppose I should say freedom of relevant information. Things that fall into the net of privacy generally don't benefit the public to know. I'm focused more on scientific research, software code, things like that. Things the public benefits from the sharing of.