To their credit, it looks like one of them did think to bring a fire extinguisher, it seems. But maybe it was just dumb luck insofar as it was only intended to be a weapon.
At the 1968 Democrat Convention in Chicago, the Weathermen (SDS) were throwing baseballs with nails in them at the cops. They did not have shields and other types of riot gear like they have today. :-O
When you are an elitist money is no object. These people had to stay some place in Chicago and hotels were quite expensive. I am sure they were not allowed to camp out in Grant Park. ;)