Police allow journalists in Ferguson riots to be attacked

After the grand jury decided to not indict Michael Brown's killer riots broke out. Two journalists, one from Russia and another from the UK, were attacked and asked police for help who noted that their assailants may be armed. So what is the point in having police there??? Another article linked on that page shows arresting journalists covering protests as well. Seems like a passive way of punishing journalism and not so good for international journalists visiting the US.

2 journalists attacked in Ferguson riots, police refuse to help [RT]