I don't think there can be a limit on Free Speech but I don't agree that what they are doing is just free speech. Surely holding up a sign that says "Thank God for dead soldiers" must constitute some kind of a hate crime?

These are acts of terrorism as far as I'm concerned. Ambushing grieving people is sheer cowardice. God help them if I wad there, or it was my family member being buried. I would kick seven bells out of them and spit in their goddammed eyes.