To me freedom of speech should stop at inciting violence, and by standing at a soldier's funeral and gloating at his death, that's precisely what this group do. They prey upon people at their weakest and most emotional in an attempt to spark a reaction, and I can't believe the restraint these families have shown thus far.
If they are allowed to continue, they should, at the very least, be held criminally accountable for the violence that will errupt one day because of their actions.