His claim to fame? Killing Trayvon Martin.
A question. What type of person would want George Zimmerman memorabilia? What type of person would want to endorse his stalking and murdering of an unarmed teenager whose "crime" was walking home and not being sufficiently submissive to a racist, gun toting, street vigilante?
Autographs are sought from celebrities. The man or woman on the corner; the local drunk; the town loser; or the anonymous median percentile average person is not a real "star". Nor does their signature or photo have any cache or quasi magical power as a type of totem or fetish which can be channeled by its owner.
Zimmerman's autograph is a way for his fans and public to idolize him.
Zimmerman's signed photo is also a way for his supporters to be closer to him, and to "own" part of his "success" and "power".
The autograph of George Zimmerman, a man who is "famous" only because he stalked, hunted, and killed an unarmed black teenager, is for those who seek it, a validation of their right to kill and murder at will those people that they deem to be the Other and somehow "less than". The South's hyper-masculine and racialized norms of honor both legitimate and sustain such logic.
If one cannot be the hero who slays the dragon, at least he or she can touch the blood soaked sword or keep company with their idealized selves.
Consequently, for a particularly racist and pitiable part of the (white) American public, George Zimmerman is their knight and role-model because he sanitized, cleansed, and protected his community (read: castle) from an outside (black) invader.