The JFK 50th Anniversary Gathering
While the Dallas Police were largely aloof, they did let about 200 who gathered to exercise their First Amendment Rights in, only to have Homeland Security push the crowd back without warning, knock a circa 4 year old girl off her father's shoulders, exercise illegal to Law Enforcement Use of Force finger grip choke grabs.
Alex Jones Interviews Vivian Kubrick. http://en.wikipedia.org/wiki/Vivian_Kubrick
A very good interview worth the watch as an on scene retrospect.
The one case the protesters really needed to cite over and over for the cameras, was left unsaid:
Miranda v. Arizona, 384 U.S. 436 (1966) @ 491 states:
“Where rights secured by the Constitution are involved, there can be no rulemaking or legislation which would abrogate them.”