There is one "Free Speech Zone" in the United States. It is contiguous with the geographical borders of the United States.
Ferguson's "free speech zone" is a padlocked no-man's-land (Boing Boing)
“When inquiries were made to law enforcement officers regarding which law prohibits gathering or standing for more than five seconds on public sidewalks,” the ACLU of Missouri wrote in its emergency federal court filing to block the apparent policy, “the officers indicated that they did not know and that it did not matter. The officers further indicated that they were following the orders of their supervisors, whom they refused to name.”
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So where and what was that free speech zone? “It’s supposed to be at the intersection of Ferguson and Florissant,” Rothert said. “There is a field there, but it is padlocked and no one can get in.”