"The woman has another son named William George Zimmerman who lived with her in 1995 and still lives in Central Florida. He is no relation to George Zimmerman, 28, who killed 17-year-old Trayvon Feb. 26, sparking national outrage and international interest.
Zimmerman traced the tweets — which he said have been retweeted by actor-director Spike Lee — to a man in California. Zimmerman has implored the man to stop and said he received this response, "Black power all day. No justice, no peace" and an obscenity."
...seems that we don't REALLY know for sure, now do we?