Fortunately and Unfortunately this is exactly what the 1st ammd is for. If it were up to me, I would be the one to pull the trigger (as long as I wasn't executed for it) but he has just as much right to do this as the KKK motherfoooockers have to fly the swastika and carry signs that read n-word.
Here is another problem, Phelps and his ilk called the police prior to showing up and told them they were going to be there AND voluntarily protested 1000' away. I too would love a local ordinance and I thought that I heard something about something that prevented them from protesting 2-3 hrs prior to a military funeral and 2-3 hrs after the funeral - but I cannot recall where I heard/read that.
I have been milling over this all day and the only thing I can think of is indecency - as in the content of his signage; it's pretty foooocking profane to include cursing (if you call the word f.ag a curse) and the graphic images of the anti-sodomizing. Additionally, I saw a sign with Matthew Sheppard which read underneath it, "Matt is in hell" - I would have to think there was some kind of copyright issue with getting that photo from the Sheppard family.
I just hate that goddamn prick and all of his cult.