Zimmerman stalked a young man through the dark streets of a city in an unmarked vehicle, brought a loaded firearm with him, left his vehicle carrying the loaded firearm for the purpose of confronting the young man (in my town, chasing someone down the street at night with a loaded gun and attempting to impede their passage on a public sidewalk is misdemeanor assault in itself), and responded to the young man's attempts to defend himself by shooting and killing him without even first warning about the gun. That's according to Zimmerman's own account. Zimmerman was not severely beaten. He was not standing his ground - he was chasing somebody. And he was the assailant, not the defender. He's a poster child for "gun owner behavior that needs restriction for the safety of the public". And if you can't figure out how to do that without infringing on your rights, other people will figure it out for you.