In Ferguson, I think we can all agree, violence is absolutely unacceptable. And those who engage in violence should be subject to due legal process and punished. However, I think we can also all agree that the fact that some engage in violence doesn't mean that the protesters don't have legitimate grievances and that those grievances shouldn't be addressed. Further, I think we can agree that those engaging in violence, wrong as they might be, wouldn't be doing such things without the injustice present that created the underlying tension.
Now, with due disclaimers that I am not drawing a 1:1 comparison, just for a thought experiment, please replace the word "Ferguson", above, with "Gaza", and read the paragraph again.