The right wing media and all people defending Zimmerman's right to murder Trayvon Martin are constantly referring to any gathering of African Americans in peaceful protest against racism as "a riot". That alone is racist, but these same people ignore the constant attempts by right-wingers to provoke anger. They just think "it's not enough that you're discriminated against, your life is of less value than mine, and I can murder you with no consequences, I'm also going to rub your nose in it, too".
While the two racists above were allowed to try and provoke a fight, this poor guy was arrested for peacefully wearing a hoodie in a mall and displaying a sign honoring Trayvon Martin (watch the video). Yet the racists will continue to claim that race has nothing to do with this case.