I did not follow the Zimmerman trial and have my own opinion on the outcome, which I reserve to myself.

As for "stand your ground" laws -- silly, bad laws. The best thing to do is not to get in such a situation in the first place and second best is to leave if you are. ONLY if you have NO OTHER option is force (not necessarily deadly force) justifiable. If you attack me and I have no where to retreat to, I have no right to kill you UNLESS you are going to kill me and the threat is real (e.g., you are coming at me with a knife); I can and would disable you by breaking a bone or whatever other step might be needed before I would kill you. For one thing it simplifies the paperwork in the cop shop.

Many homes in the US have "mail slots" -- we had one in Indiana. You have no more right to harm the mailman than you do to harm anyone else.