Sorry but I'm not really clear on what you are saying here. I mean, it seems quite straightforward and obvious to me how to identify abusive, vitriolic harassm

Sorry but I'm not really clear on what you are saying here. I mean, it seems quite straightforward and obvious to me how to identify abusive, vitriolic harassment, and how to recognise legitimate criticism of someone's viewpoints. Perhaps I am misreading your point, but you seem to be arbitrarily conflating the two?