...what? I don't think they're talking about hallucinations here, they're talking about public opinion.
I think it’s really swell how the last 10 years have made it so the basic difference between fact and opinion is not totally obvious.
Using your example --- as far as "risk" to the public is concerned, which would be more pertinent info --- the fact that this person is a murderer or your low opinion?
Public opinion, or popular opinion, is the collective opinion on a specific topic or voting intention relevant to society. It is the people's views on matters affecting them (From Wikipedia)
It has nothing to do with fact. It broadly represents peoples views, factual or otherwise.