What Do The Zimmerman Verdict Protesters Know That The Jury Did Not Know?

From Samizdata, "So what do these people know that the jury did not know?" by Perry de Havilland:

So my question is… so what do these people [protesting the Zimmerman acquittal] know that the jury did not know? Why exactly are they protesting the verdict? I have not read any coherent arguments as to why the jury in this case got it wrong.