Apparently since the 1% became sufficiently afraid of the 99% so as to regard the Constitutionally-guaranteed rights to assembly and free speech as security threats.
This notice gives a flavor of what to expect for the September 17 celebrations of the anniversary of Occupy Wall Street (click to enlarge; hat tip nathan): Read more at http://www.nakedcapitalism.com/2012/09/police-state-watch-nypd-to-install-checkpoints-demand-id-in-lower-manahttan-on-ows-anniversary.html#VVRVlY2F5qgodIUB.99