Richard,
Our hearts go out to you. I'm always saddened by the cruelty we witness in the world. Our pets are like family and we take their wellbeing to heart. My constant companion "Dually" is like a son and best friend to me. The thought of someone causing him harm boils my blood.
Regarding the confrontational posts:
I'm an avid hunter and consider others like myself to be "ambassadors" of the sport. This crime torques me in two ways. One, the cruelty to the innocent pets and two, that someone has slandered our sport by shooting two animals while under the guise of hunting. I have no tolerance for those that hunt unethically, unsafely or commit poaching or slaughter. It's our duty as "ambassadors" to make sure "Joe Public" has a favorable impression of our sport. This includes treating the game with respect, leaving no trace of our activities on the land and respecting the landowners and general public. It hacks me off when I see someone wearing camo doing something distasteful or a bloodied animal tied to a roof rack. These are images that implant a negative opinion of our sport.
I don't believe you're vendetta is aimed at the hunters, as we share your outrage. The idiot(s) that committed this atrocity are not hunters, they're criminals, plain and simple. Any true hunter, would turn them in to the authorities.