(NBC) - Today in Washington, the U.S. Supreme Court hears the first in a series of important free speech cases.

A California man was banned from protesting at an air force base after he crossed the boundary of an official protest area - and he says that's a violation of his free speech.

John Dennis Apel was such a pesky anti-war protester that he was formally banned from an area set aside for protesters at California's Vandenberg Air Force Base, and he's protesting again today - at the Supreme Court. He says his free speech rights were violated. "We should be able to stand there and say - this is not right," declares Dennis Apel, Defendant.

Protesters are allowed to voice their opinions on a public roadway outside Vandenberg Apel stepped outside the lines - was arrested and banned. Then arrested again when he came back. "The reason its' important is - because all of our Constitutional rights seem to be kinda slowly getting eroded away one piece at a time," said Defendant Dennis Apel.

The government argues that it wasn't trying to stifle voices of protest - just protecting national security. "If a public roadway makes a place somewhere where people can protest and express themselves THAT might be a big security problem for the government," said Georgetown University Professor Paul Rothstein.

Along with a case that challenges protest buffer zones outside of abortion clinics. The justices are hearing arguments this term that are destined to test the boundaries of free speech.