I think this problem doesn't really lie along the axis of centralization of power. Google is taking on policing power because the actual police are more or less

I think this problem doesn't really lie along the axis of centralization of power. Google is taking on policing power because the actual police are more or less absent on its platform (because of technical competency and complex jurisdictional issues). Is that an example centralization or decentralization? It's a little of both. The real problem, IMO, is best described as "public power in private hands."