This article lists numerous incidences where the President was prevented from being exposed to signs of dissent. Protesters are penned like sheep, into "free speech zones" where they have the freedom to speak, but into a silent void where their speech goes unheard. This technique of crowd control has been used at many major public events for the past decade allegedly to keep peace. Protesters, often not aware of the repercussions of their complicity, go along with whatever the police prescribe.
People who resist are arrested, and released, but only after their opportunity to speak has passed.
