Errr what?
I read the link OP posted, ok, but at what distance are they allowed at the funeral to protest?
Regardless of nutjobs or not, i think that there are let's say more appropriate places to bleat your beliefs than a funeral, am i right?
No respect for the dead comes to mind here.
Sorry but i think that in this case certainly that it is in bad taste.
The mourners, would they hear the protesters? See them? Whilst they pay their respects to the deceased?
I know i for one would be outraged and disgusted if i was at a military funeral of a family member or close friend, letalone a funeral in general.
Sorry but that's b***crap!
Protest if you must, but do it with a bit of respect, and certainly not at a funeral

Doesn't matter what your beliefs are.
And as for the matter of 'freedom of speech' arguement?
Moot.