A recent case in Queensland, Australia, involving a child sex-offender who had a case dismissed by a judge due to a belief by the judge that an impartial jury would not be found, weakness in the prosecution case and possibility of time served being at least equal to, if not in excess, of the possible sentence, has resulted in extensive public unrest by people living in the area where the offender has been housed.
Perhaps, as indicated by the italicised portions, he is not only not guilty (prosecution's weak case), but has served time for nothing. Despite the mindless mooing emotionality of the easily manipulable mob, he might be innocent. If he is found in flagrante dilicto, in the act, the prosecution would have a good case. If the case is that weak, tie goes to the runner!
Think of the rape allegations in southern usa accusing a sports team of rape. An overactive prosecutor commited misconduct in order to 'score' a conviction. The mooing mob was ready to hang en all. Oops!...
I don't see the abovementioned case, what i know of it, as cause for people to 'take it into their own hands'.
Other cases, perhaps.
"Nothing is true. Everything is permitted!"
-Hassan i Sabbah (old man of the mountain)