That's not what I'm talking about. The platforms need to create a new form of "legal process" where these issues are defined and adjudicated in an open process. Google et al are de facto a new layer of government, and they need to act like it. Currently, they are trying to act like a "(mostly) benevolent dictatorship" and finding out that the hard way that you can't actually please everyone. The proper way to handle calls for censorship/banning/etc is to tell them to take their grievances to the formalized judicial process and/or argue for changing that process in the formalized, open "legislature".
For a much better explanation, I highly recommend watching Raph Koster's talk (my previous [2]). Even though it was at GDC and initially talks about VR and MMOs, the talk is not actually about games; it's about the ethical and social responsibilities of creating social spaces, and the may ways we've tried to solve their problems in the past.
The same thing we use when enforcing the rules of any infrastructure: publicly accountable and transparent due process. These problems will continue until big tech implements a proper rule of law[1]. They will continue[2] to be responsible for these difficult decisions as long as their platforms idea of justice is the rule of man[2].
[1] https://en.wikipedia.org/wiki/Rule_of_law
[2] https://www.gdcvault.com/play/1024060/Still-Logged-In-What-A...
[3] https://en.wikipedia.org/wiki/Rule_of_man