Twitter and Facebook have so much data that there is no feasible way to archive it for future study. But even if that were done, it would be impossible to determine in the future, from the data, what users would have seen in the past.

I disagree with the ho-hum conclusion of the article. Given the way these networks influence politics, the question of what they did will be important to study in the future. If we have in the future a political system that permits people to research such questions, the question of why we still have such a system will depend on it.