Missing from this otherwise informative conversation is the negative economic incentive for platforms to limit any use of their product. Platforms are aware that zero limiting will ultimately the destroy the value of their product for a majority of their users and they will lose money. OK, what do they limit? The silent assumption in the middle to upper levels of management is to NOT to act very strongly in limiting "bad" communications so that the bottom line is not hurt. In the deep amygdala of these managers resides the instinct that every limit to access is taking money out of the pockets of the owners. It could be 1/10 of a cent, but that adds up to Billions. I see from Renee's Wikipedia page that she seems to have recognized this issue in an article she wrote (with others) in the Scientific American "It is Time to Open the Black Box of Social Media." (I have not read it, but one of the co-authors is Brendan Nyhan, a Dartmouth Professor I greatly respect.)