If there is one takeaway from the Cambridge Analytica story and the Facebook hearings and so on, it is that democracies, and that means democratic governments, need to get a handle on these phenomena right away, because the general public does not and cannot know the extent to which giving away apparently “impersonal” data might, in fact, reveal our most intimate secrets.

Yes, we should be very concerned about putting direct personal data out onto social media. Obviously, putting “Democrat” or even “#Resist” in your public Twitter profile tells anyone who asks what party we are in. We should be asking hard questions about whether it is wise to allow even that minimal kind of declaration in public and whether it is wise to allow it to be stored in any form, and by whom. But perhaps even more seriously, and much less obviously, we need to be asking who is allowed to process and store information like that, regardless of where they got it from, even if they did not get it directly from us.