For reasons I don't understand, the "audiophile" groups on Facebook, at least the general ones that aren't focused on one brand or kind of equipment, attract more than their share of mean-spirited folks, especially those who don't "believe" in things like cables. I understand there is plenty of room for debate on cables and other so-called tweaks, and that both sides of the issue are represented here, in our membership, but at least here the discussion is civilized and relatively balanced. On those FB groups, it's pretty one-sided, and just plain nasty, degenerating rapidly into ad hominem attacks. As far as they're concerned, if it can't be measured, it doesn't exist, and anyone who believes otherwise is a fool waiting to be fleeced, and/or a charlatan waiting to do the fleecing.
What's worse is that these posts don't stay among the general group threads, but bleed over immediately into their classified ads (if the group has any). Heaven help the audiophile who posts an expensive power cable for sale. Within minutes there will be posts decrying the cable as snake oil and not worth the cost of shipping, effectively spoiling the sale. I've made the mistake of wading into one or two of these, suggesting that what these self-proclaimed "defenders of the realm" are doing might be considered rude. I asked one if they patrol the used car lots in their city, interrupting sales pitches to warn buyers about cars they think are crappy. They just about took my head off.
I finally quit all the ones I'd joined, other than those associated with specific brands of equipment. Though I recently joined The Music Room's (dealer in the Boulder, CO, area) group, at the request of the founder. So far it seems like a reasonable group of people.