For some reason FB and the like want to observe, catalog and filter it. If they wanted it stopped they could just block the posters, computers or devices posting it. With their level of tech and analysis it would be easy to ban permanently a poster even behind things like a VPN, but they want it at least to pass through...
Heck, their main focus could be studying the content mods to see what and how horrid crap affects them.
Studying the mods?
That makes sense.
Facebook=CIA=MKUltra etc.
Oooh that’s creepy.