Zoning Regulations on Free Speech
A controversy earlier this year at the University of Central Florida, discussed in this article, raises the common use of "free speech zones" to stop protests. The essential problem with speech zones is that they arbitrarily prevent all speech throughout most of the campus. In this case, no one imagines that the Students for a Democratic Society chapter were trying to blockade anything. They just wanted to talk to people in an area where administrators feared it might become too congested, I suppose. That's nowhere close to a rational reason for an absolute prohibition on free speech and assembly.