This is one of many various large signs used by Fred Phelps of the Westboro Baptist Church. Fred Phelps and Westboro Baptist Church are responsible for the websites http://www.godhatesfags.com and http://www.godhatesamerica.com.
The "AIDS Kills Fags Dead" was, in fact, seen at the Matthew Shepard funeral. The Westboro Baptist Church, as a practice, pickets funerals of gays and lesbians, especially those near Topeka, Kanasas. They also travel to high profile funerals of gay people, such as the Matthew Shepard funeral was, mainly for media attention. Of course, "Fag and sodomite" to Fred Phelps means anybody who doesn't agree with him.
The tragic and sickening irony was that there was nobody to protect Matthew Shepard from the homophobes that beat him and left him for dead, but the Westboro Baptist Church had a barricade and police protection to picket his funeral.