Thugs in Sacramento surrounded and besieged a group of protesters, then ordered them to disperse (which the thugs stopped them from doing), then arrested the protesters and journalists covering them.

To force people to do A, and blame them for not doing B instead, displays contempt for the very idea of justice. However, if the thugs had permitted them to disperse, that doesn't excuse doing so to sabotage a protest against the thugs' killing.