I'm not sure. I only heard about it from a Fog God follower. The Fourth followers destroyed an obelisk important to her. They have been given powers by their god, too.

The Fourth either has very few followers or they are secretive. I have only seen one person on the network out themselves as a Fourth priest so far. I couldn't blame them for being cautious. I doubt the Fog worshippers are kinder to their enemies than to the humans.