The Ride Above Hate FB page that is discussed on the Off Course section is certainly a little odd and random, and appears to have no-one commenting or liking it. OP says she just started it recently, but when I went into search to try to find it, there was a COTH comment thread on it from 2014, so not that new.
I can’t see evidence that it belongs to the Dressage Hub person, though. How did you figure this out? I guess my doxing skills are not as good as I assumed! 
The Riding Above Hate FB group is unfocused, and has the feeling of someone who didn’t want to come straight to the point of whatever the issue was. I thought quite likely a 15 year old who’d had a barn fight with her BFF or something like that. But, rather oddly, it does have a selection of dressage competition videos.
I also went and looked at the Dressage Hub FB and website, just to see what all the fuss was about.
i don’t love what that mouth and tongue are doing, but I also don’t see a blue tongue. I barely see a tongue at all under that foam.
Also flicked back over past posts on the DHub website, and found this pitch for donations from last winter.
http://dressagehub.com/?p=812
All is not right here, on many levels.
I wasn’t following the DHub website or FB group and don’t know the folks involved, and it seems to be a somewhat marginal one-person effort. Though when I look at the FB site it does have over 30,000 followers, so that is a pretty wide reach.
If the showfolks don’t like what she is doing, they can ban her from videotaping (the shows are on private property). They can also send a cease and desist letter from a lawyer if she is defaming them.
Head injuries really are a major problem in the horse world, as I’ve said before
and account for some percentage of horse world cray cray, for sure.