If it constitutes a threat to the children, it's not legitimate. Do you believe it is innocent protesting or intended to be a threat?
You raised an interesting point. "Punishing the father" for what exactly? Has the father committed anything illegal? Who are the accusers and when was the due process observed? Who meted out the sentence and the penalty? And no it is not a legitimate activity, barely legal if.
And the girl in the school is dismembering children alive? Well, you're right then, she should be the brunt of the protests, what an evil child!