Unfortunately it isn't "start acting", the violent cycle began a while back.  I live in the Ala Moana area, and the homeless are far from passive.  Many are younger males, that have taken to walking around with sticks, iron rebars, and they are not stopped, and these weapons are not confiscated.  I have walked through the McDonald's parking lot on Keeaumoku and picked up open folding knives, syringes, all in full view of children, strewn through the parking area.  The hostility was relegated to amongst themselves before, but now they are directing it towards pedestrians, and businesses in the area.