It is my belief that some people just cannot accept most wrongful convictions (as being wrongful convictions), even when the evidence is very clear that someone is innocent, as with Scott Peterson (say) or Jodi Arias (which does seem to be a difficult case for many). Or even Amanda Knox (say).
Nancy Grace would be one such person. Perhaps because she was once a victim of a crime, perhaps for other reasons, I do not know why some, even perhaps many, people have this “guilt bias”. I think it is a fairly natural human disposition, perhaps a result of evolution and natural selection. It is safer to be suspicious of someone than too trusting!
I find it is simply a waste of time discussing a wrongful conviction with these people both my own time and theirs.
So to avoid wasting my time, and theirs, I block them.
I guess there about 20 such accounts. It doesn’t necessarily mean they have been uncivil or rude.
Trial by Media 
I think it’s more a matter of institutional and collectivist loyalty. As I’ve written elsewhere, official accusation is already a statement of the collective consensus. Many people instinctively follow and adhere to a consensus by the collective and just as instinctively recoil against any challenge to it. It’s a little like an “our team – their team” mentality, but it’s broader and deeper than that and almost defines a person’s outlook on many and varied things. That’s why they seem to get personally offended or otherwise respond very aggressively to any challenge.