As more and more formerly public places are privatised and the veneration of private property as an ideal above all others continues, the USA is simply running out of places where you're even allowed to protest. And that's not even considering so-called 'free speech zones', as if free speech is limited to a fucking place.
This is free speech: https://en.wikipedia.org/wiki/Hikoi#/media/File:Hikoi_FS.JPG
In the USA these people would be arrested for blocking a road.