I'm not sure you can see this as a persistent failure in terms of FB (and similar) fighting against an unstoppable tide of ignorance. It's far more easier to se

I'm not sure you can see this as a persistent failure in terms of FB (and similar) fighting against an unstoppable tide of ignorance. It's far more easier to see Facebook (and similarly Google with Android, for a very long time) sabotaging the effort from the start. A user absolutely can choose what they share with Facebook, but Facebook makes no effort to tell you why you should edit the defaults. Instead, you have to click an edit button, and look at a list of checkboxes, and understand what each thing means, and double and triple check that this doesn't override your personal privacy preferences or have some other unintended side-effects. The default expectation from Facebook (and similar) is biased heavily against the user, purely by virtue of it being opt out. It depends on users not being educated well enough, and giving them a good reason to care less about being more judicious with their profile.